Halakhah zu Tehillim 19:9

To preserve your sense of sight, take the following precautions: Do not come suddenly, all at once, from a dark place to a well-lit one. If you need to enter from a dark place to a lighted one, open the door a bit and look at that small amount of light for a few moments, then open it more and again look at that light for a few moments, and then open it completely. Do the same when going from a lighted area to a dark one. This is because the shift from light to darkness, or from darkness to light, without any transition, damages the sense of sight. For this reason G-d, blessed be His name, in His great mercy created the world in such a way that the sun shines upon the earth little by little, not all at once, and likewise sets little by little. For this we bless Him as “the One who illuminates the earth and those who dwell upon it, with mercy,” meaning that He mercifully makes the sun shine little by little, and not suddenly, all at once. Reflected light from the sun—meaning that the sun shines on something and from there the light is reflected—is a light that is damaging to the eyes. Therefore you should take care not to dwell in a house where all the windows are on the north side, because the sun does not come to the north, so that all the light that comes from that side is only reflected light. Similarly, even if the windows are on the eastern, southern or western sides, if you cannot see the sky through the windows—for example, if there are high walls opposite them—then the light that comes through them is also only reflected light. You should take care not to be occupied with writing, reading a book, or any sort of detailed work by twilight, or in the middle of the day, when the sun’s light is at full strength. You should also not do too much writing, reading of books with fine print, or any other sort of detailed work by candlelight at night. Too much staring at the color white also damages the eyes; that is why the sky appears blue, not white, so it should not damage the eyes. Likewise, staring excessively at a bright red color, or at fire, is also damaging. Smoke and sulfurous fumes are also damaging, as are fine dust and wind that blows into one’s eyes. Also too much walking and large strides, and excessive crying [are harmful], as the verse says, “My eyes are spent with tears.”⁹Eichah 2:11. Most detrimental of all is excessive sexual intercourse. By contrast, “the commandment of G-d is clear, enlightening the eyes.”¹⁰Tehillim 19:9.

It is written, “Serve the Lord with gladness” (Ps. 100:2)¹Berakoth 31a. and “Serve the Lord with fear” (Ps. 2:11), but how so? ²The Midrash on Psalms, trans. William Braude (2 Vols.; New Haven, Conn.: Yale University Press, 1959), II, 147.(both fear and gladness?) If a man is over-joyful, let him recall the day of death,³Berakoth 31a. this is fear. If he is sad, let him rejoice his heart with matters of the Law,⁴Shabbath 30b. as it is written, “The precepts of the Lord are right rejoicing the heart” (Ps. 19:9).

To not conclude the judgment by estimation: That a court only kill the accused with witnesses that testify about the same matter about which he is to be killed; that they actually saw him with their eyes, [not] that they testify against him based on strong indications. And about this is it stated (Exodus 23:7), "and an innocent one and a righteous one you shall not kill" - meaning to say, be very careful not to kill a person about whom it is possible that he did not do what they said that he did. And so is it explained in Mekhilta d'Rabbi Yishmael 23:7:2, as there they said, "If they saw him pursuing another to kill him, the knife in his hand, and they [warned him, 'If you kill him, you will be killed.' And the witnesses] averted their eyes [and did not see him striking him] and afterwards they found him (the victim) in the death throes, the knife dripping blood in the hand of the murderer — I might understand that he is liable [for execution. Hence,] we learn to say, 'and a clean one and righteous one you shall not kill.'" Behold, because they averted their eyes at the time of the striking, this one is exempted. And the matter is proper and fitting to be like this. As if the Torah had permitted to establish the parameters of punishment with strong possibilities, it would come out from the matter that sometimes we would kill people for something they did not do, as there is great breadth to the possible. And know this and understand it, as it is a clear thing. And therefore, He, may He be elevated, closed this gate and commanded us about it. And all of "the precepts of the Lord are just, rejoicing the heart" (Psalms 19:9). And also included in this negative commandment is one about whom two witnesses have testified that he committed a [different] sin; for example, that one testifies that he did work on Shabbat and one testifies that he worshiped idolatry, such that this one is not condemned by their testimony, as it is stated, "and an innocent one and a righteous one do not kill." And so did they, may their memory be blessed, say (Mekhilta d'Rabbi Yishmael 23:7:2), "If one testified against another that he worshiped the sun, and another, [that he worshiped] the moon, I might understand that they combine (to constitute the necessary two witnesses). [Hence,] we learn to say, 'and an innocent one and righteous one you shall not kill.'"

We do not stand to pray in the midst of (ie. immediately after) judging a case, or in the midst of [studying] Jewish law, so that one's heart will not be troubled with it (ie. he will be distracted by it), rather [we stand to pray] in the midst of [studying] conclusive Jewish law. Rem"a: For this is also like being in the "midst of joy", because of [the verse] "the precepts of Hashem are upright, delighting the heart" [Psalms 19:9] (Tur, Orach Chaim 93:1)

The words of the Torah gladden the heart, as it is said, "The precepts of Hashem are upright, gladdening the heart" (Psalms 19:9). Therefore, it is forbidden to study Torah on Tishah beAv, except for subjects that sadden the heart, such as the chapters of the book of Jeremiah,¹¹According to Shulchan Aruch 554:2, it is also permitted to study commentaries on Jeremiah and Job. regarding the ominous events he prophesied, omitting the verses of consolation. Also the verses foretelling the punishment to be meted out to the nations of the world that are written there, should be omitted. It is also permitted to study the Book of Job, as well as Midrash Eichah. [The following Talmudic selections may also be studied:] the Talmud, chapter Eilu megalchin, (Moed Katan, 3rd chapter), which deals with the laws of a mourner, and a person who was excommunicated, and the Aggadic portion of the chapter Hanizakin (Maseches Gittin 55b), and in the Jerusalem Talmud, the last part of the Maseches Ta'anis, which discusses the destruction of the Beis Hamikdash. But even the chapters you are permitted to study, you are forbidden to study in depth, to find an answer to a difficult question or a homiletic interpretation, for that would gladden the heart. Any subject you, yourself, are permitted to study, you are permitted to teach to children. You are permitted to read the entire order of daily prayers, even the Mishnah of Eizehu mekoman¹²The portion of prayers that deal with the order of sacrificial offerings should not be said, with the exception of the daily sacrifice. (See Mishnah Berurah 554:7) (What is the location [of the offerings?]). But you should not say Ma'amados, even if you are accustomed to saying it every day.

That He prohibited the king from having much money specifically for himself. And that is His saying, "and he may not have silver and gold for himself in great abundance" (Deuteronomy 17:17). And the measure of this is that its amount only be according to that which is required for his chariot and his designated servants. But it is permitted that he amass money for the benefit of all of Israel. And God, may He be exalted, has already explained the reason for these three commandments - meaning to say, "he may not have many horses," "he may not have many wives" and "he may not have silver and gold for himself in abundance" - in Scripture. But because their reason and cause was known, a veering away from the law occurred. [This is] that which is already famous in the story of King Shlomo, peace be upon him - in spite of the great level of his knowledge and wisdom, and his being a "friend of God (YedidYah)" (II Samuel 12:25). They, may their memory be blessed, said (Sanhedrin 21b) that there is a hint and message with this to people: That if they knew the reasons for all of the commandments, there would be a veering away. [For] if this one, who was so complete in wisdom and of such great stature, could already imagine and think that this [forbidden] act is not necessarily a cause for that sin; what will be when all of the masses with their weak minds will talk about them and say, "This would not be prohibited or this not commanded except for this. I will be careful about the thing for which this commandment was commanded, and I will not pay attention to it [since it was only meant as a fence]!" But then the law will be destroyed. And hence God, may He be exalted, hid their reasons. But there is none of [the commandments] that does not have a reason, a benefit and a cause. However most of these reasons needed to be hidden; for the intellect of the masses will not grasp and understand them. But they are all like the prophet testified - "The statutes of the Lord are right, rejoicing the heart; the commandment of the Lord is pure, enlightening the eyes" (Psalms 19:9). And I shall ask assistance from God to fulfill that which we are commanded about, and to stay away from that which we are prohibited. (See Parashat Shoftim; Mishneh Torah, Kings and Wars 3.)

The root of this commandment is known - as there is in it a benefit to all, and to the ordering of the state; as forgetfulness exists with all [people, and] also their beasts and all of their animals flee here and there. And with this commandment that is among our people, beasts and vessels will be safe in every place that they may be in our holy land as if they were under the hand of their owners. 'And all of the directives of the Lord are straight, they rejoice the heart.'

1. Tisha b'Av is forbidden for washing, anointing, wearing leather shoes, and marital relations. It is also forbidden to read from the Torah, Nevi'im, and Ksuvim and to learn mishna and midrash and gemara and halacha and aggada, because it says, "The precepts of God are right, gladdening the heart" (Tehillim 19:9). Schoolchildren are idle on it. One may read Iyov and the bad things which are in Yirmiyah, but if there are between them passages of consolation, one must skip them.

It is from the roots of this commandment [that it is] in order to restrain the villains from this evil deed, and that the daughters of Israel should not be as if abandoned. Since if the rapist thinks he can fill his desire with her and [just] walk away, it will be light in his eyes to do so many times. But if he has in mind that she will be tied to him and he will be [held] responsible for the obligation of [her] sustenance, clothing and appointed times, all of his days; and that even if he gets sick of her, he will never have the option of divorcing her; and that he he will have to give to her father fifty silver [shekel-coins] immediately - he will truly suppress his [evil] impulse and prevent himself from doing this villainy that comes with such a penalty. And there is also in this a little comfort for this poor embarrassed woman in that she will stay with him forever, lest another man would embarrass her with this evil thing that happened to her. 'And the ordinances of the Lord are straight, they rejoice the heart.'