Halakhah sa Mga Awit 134:1: Shulchan Arukh HaRav, Kitzur Shulchan Arukh & Shulchan Arukh, Orach Chayim

And it is already known what is argued about this stringency in the book of the Zohar. Such is said in the Gemara that "midnight" is a time of will, as it is written, "And it was the half [way point] of [the] night and G-d struck the every first born..." (Shemot 12:29). And they also said that one who occupies himself with Torah at night, the divine presence is in front of him as it says, "Arise, cry out in the night, at the beginning of the watches; pour out thy heart like water before the face of the Lord" (Lamentations 2:19). Meaning, the divine presence is found with you and " beginning of the watches" is at "midnight" (if he can not get up at half way through the night, he should get up at the beginning at the beginning of the third watch (the beginning of the last third of the night)). He that is involved with Torah at night, a string of kindness is pulled on him, as it says, "By day, may the Lord command His kindness, and at night, may His resting place be with me..." (Psalms 42:9). This is called a servant of G-d as it is written, " Behold, bless the Lord, all servants of the Lord who stand in the house of the Lord at night." (Psalms 134:1). It is proper to prepare a rooster to awake him from his slumber and "midnight", which was the doing of Rabbi Akiva. He pulled along with him a rooster, even when he would go on his travels so that it would awake him at "midnight". If the rooster did not awake him, he would pay someone to awaken him.

If you are able to awaken and rise at midnight⁶According to Mishnah Berurah somewhat before midnight. to recite the prayer of Tikun Chatzos⁷These are prayers lamenting the destruction of the holy Temple. it is most praiseworthy, as it is said: "Rise, cry out in the night at the peak of the night watches" etc.⁸Lamentations 2:19. For the Holy One, Blessed is He, [also] laments at that time, as it is said: "Hashem from His high place cries, and from the Dwelling Place of His Holiness He sends forth His voice, as He cries for His Sanctuary."⁹Jeremiah 25:30. And He says, "Woe unto the children that on account of their sins I destroyed My house, and I burned My Sanctuary, and I exiled them among the nations."¹⁰Maseches Berachos 3a. If you cannot rise at midnight, you should nevertheless exert yourself to rise before daybreak, as said King David, may he rest in peace, "I will awaken the dawn,"¹¹Psalms 57:9. [He meant] "I awake the dawn but the dawn does not awaken me." You may recite Tikun Chatzos, even after midnight and then afterwards engage in Torah study according to your ability [or capacity]. A lesson in Mishnah is preferable to any other study, (and by so doing you will be worthy of [your] neshamah [soul] [as inferred from the word] Mishnah which has the same letters as neshamah.¹²נְשָׁמֶה - מִשְׁנֶה If you are not capable of this [studying Mishnah], you should recite Psalms and Ma'amados¹³Various selections of Scripture and other sources. and study works of ethics. A little learning or recitation with concentration is better than a great deal without concentration. Rabbi Chiyah taught: "Whoever studies Torah at night the Divine Presence is before him, as it is said: "Rise, cry out in the night at the peak of the night watches. Pour out your heart like water before the Presence of Hashem."¹⁴Lamentations 2:19. This verse signifies that the Divine Presence is before us at that time. It was also said by our Sages, of blessed memory: "Whoever studies Torah at night is called a servant of Hashem, as it is written: [Behold, Bless Hashem] all [you] servants of Hashem who stand in the House of Hashem, during the nights."¹⁵Psalms 134:1. During the short nights when it is difficult to rise so early, you should at least endeavor to rise while there is sufficient time to prepare yourself to go to the synagogue to pray together with the congregation.

Chapters of the Psalms, and other sections of the Torah, Prophets and Scriptures, in which all are not sufficiently fluent, must not be recited by heart. Even someone who knows [them sufficiently] to recite them by heart should be careful not to recite them by heart.¹⁶According to Mishnah Berurah you may recite Psalms by heart, since it is similar to saying prayers. However, a blind person may recite them by heart.