Halakhah sa Deuteronomio 17:19: Mishneh Torah, Kings and Wars, Mishneh Torah, Tefillin, Mezuzah and the Torah Scroll & Mishneh Torah, Positive Mitzvot

When the king sits on the throne of his monarchy, he must write a Sefer Torah for himself, this in addition to the Sifrei Torah which were left for him by his forefathers. He checks his Sefer against the one¹⁸It was an ancient Sefer Torah. in the Temple Courtyard, in accordance with the Court of Seventy-One. If his forefathers did not leave him a Sefer or if it was lost, he has to write two Sifrei Torah. The first one will be kept in his Repository; this is the same Commandment which all of Israel must observe. The second one must never leave his side, other than when he goes to the lavatory or the bath or a place where it would be improper to read from it¹⁹e.g. a cemetery.. When he goes to war, it is with him. When he returns, it is with him. When he sits in judgment, it is with him. When he eats²⁰Lit., reclines., it is next to him, as it says, “And it shall be with him, and he shall read from it all the days of his life” (Deut. 17:19).

The king must not drink himself drunk, as it says, “not for kings is the drinking of wine” (Proverbs 31:4). Rather, he must be engaged in Torah and the needs of Israel, day and night, as it says, “and it shall be with him, and he shall read from it all the days of his life” (Deut. 17:19).

Similarly, he must not be preoccupied with women. Even if he has but one (wife) he should not be found by her all the time as with the fools, and as it says, “Give not your strength to women” (Proverbs 31:3). Regarding the steering of his heart away, the Torah has already been exacting and said, “Do not veer your heart” (Deut. 17:17). For his heart is the heart of the entire Congregation of Israel. Therefore, Scriptures has attributed to him that which is written in the Torah, more so than any other member of the nation, saying, “all the days of his life” (Deut. 17:19).