Midrash su Esodo 13:9

The Holy One, blessed be He, said that there is no ailment that does not have its cure; and the cure and drug for every ailment have been predetermined. If you desire your body to be free of pain, devote yourself to the Torah, for it is a healing balm to the entire body. We know that it is a cure for the head, since it is said: She will give to thy head a chaplet of grace (Prov. 1:9); for the heart, as it is said: Write them upon the table of thy heart (ibid. 3:3); for the neck, since it is written: And chains about thy neck (ibid. 1:9); for the hands, as it is said: And it shall be for a sign unto thee upon thy hand (Exod. 13:9); for the navel, for it is written: It shall be health to thy navel (Prov. 3:8); and for all of the bones of the body, as it is said: And marrow to thy bones (ibid.). R. Joshua the son of Levi declared: The Holy One, blessed be He, demonstrated this when he gave the law. Prior to the departure of the Israelites from Egypt, some of them had been injured as a result of the hazardous labor they performed with mud and straw. Stones from the buildings had fallen upon them, breaking their hands and mutilating their legs. The Holy One, blessed be He, said: It is not right that I should give my law to imperfect men. What did He do then? He instructed His angels to descend and heal them. Whence do we know that none of them were blind? It is said: And all the people perceived the thunderings (Exod. 20:15). How do we know that there were no deaf ones among them? It is written: We will hear (ibid. 24:7). Whence do we know that there were none among them without hands? They said: We will do (ibid.). How do we know that there were none with crippled legs among them? It is written: And they stood at the nether part of the mount (ibid. 19:17). R. Judah the son of Simon said: Because they were as new, the Holy One, blessed be He, called that month “master of renewal.”¹²The giving of the Law, which took place in the third month renewed Israel both spiritually and physically. Whence do we know this? We know it from what is written about this matter in the section In the third month.

"That the Torah of the Lord be in thy mouth" -- to exclude women [from tefillin]. What is exemplary about tefillin? They are a positive time-triggered commandment from which women are exempt. So too, are women exempt from all positive time-triggered commandments.

How do we know that the passages are to be on one roll of parchment? We can deduce this from the fact that it is written: And it shall be for a sign unto thee (Exod. 13:9)—for thee, and not (just) for others.²⁴Just as it appears on one container to other, so it should be one parchment for you. What is the size of the phylactery strip? R. Rami the son of Abba stated that R. Simeon the son of Lakish said: It is the size of the snapping finger. Which is the snapping finger? The middle finger. And its width is that of the thickness of barley corn. The law enjoins one to put the hand phylactery on first, and then pronounce the blessing: “Our God, who sanctifies us by His commandments and has commanded us to put on the phylacteries.” After that one dons the head phylactery while offering the blessing: “Our God, King of the Universe, who sanctifies us and has commanded us concerning the law of the phylacteries.” However, if he speaks in between the hand phylactery and the head phylactery, he is guilty of a transgression for which he must return home from the battlefront.²⁵As laid down in Deut. 20:8, according to the rabbis; one who has a transgression on his conscience should not remain on the battlefield of a war of conquest, aside from Joshua’s wars. This transgression is considered serious enough to fall in that category. But if he pauses while putting on the hand or head phylactery with the phrase “His great name” or to recite the Kedushah,²⁶A prayer in the ritual; “Holy, holy, holy is the Lord of Hosts.” he need not return from the battle. He must start over again, for each phylactery requires two blessings.²⁷One for itself and one for its companion phylactery. If recited together they support each other. However, if one should interrupt the blessings of the phylacteries in order to respond with the words “His great name” or the Kedushah, he has canceled the first blessing and must recite both of them again. Surely it is not necessary to state that if he discusses secular matters during that time, he is guilty of a serious transgression. When he takes off the phylacteries he must remove the head phylactery first and then the hand phylactery.

One might think that the law about the phylacteries applies, likewise, to women. Hence Scripture says: That the law of the Lord may be in thy mouth (Exod. 13:9). And who are they that study the law? Men. Therefore women are exempt from so doing, for they do not devote themselves to the law. It may be possible to conclude that the law of phylacteries applies to children. Therefore Scripture says: And Thou shalt keep it; and that applies to all who are diligent in the study of the Torah and in the performance of good deeds. Hence a child is exempt. But if a child is a Bar Mitzvah or well informed, he must fulfill the law. It is possible that one may neglect to examine the phylacteries, and so Scripture says: from year to year. From this statement they conclude that a man should examine his phylacteries at least once every twelve months. From year to year is mentioned in this verse, and further on For a full year shall he have the right of redemption (Lev. 25:29) is stated. Just as in the former case a year means twelve months, so also in the latter instance a year implies twelve months. This is the opinion of the School of Hillel. The School of Shammai, however, argues: One need not examine them ever after. So Shammai said: “These are the phylacteries of my mother’s father.”

— But in that case, perhaps there should be four separate receptacles of four sections each. It is, therefore written (Shemoth 13:9) "and as a remembrance between your eyes" — one receptacle for four totafoth.

R. Eliezer says: "on your hand" — the height of the hand. You say "the height of the hand," but perhaps "your hand," literally, is intended. It is, therefore, written (Shemoth 13:9) "And it shall, therefore, be for you as a sign" — "for you as a sign" (i.e., on the upper arm) and not for others as a sign (i.e., not in the palm of your hand.)

(Shemoth 13:9) "upon your hand" — the left hand, as it is written (Isaiah 48:13) "My hand also has founded the earth, and My right hand has spanned the heavens," and (Judges 5:26) "She sent forth her hand for the (tent-) peg and her right hand for the laborers' hammer," and (Psalms 74:11) "Why do You withdraw Your hand, and Your right hand, etc." — whence we see that "hand" (by itself) in all places is the left hand.