Halakhah su Salmi 31:6

In sum, according to the enactment of the Sages, one must recite the first paragraph of Shema and Ha-mapil before going to sleep, but the remaining psalms are not required. Nevertheless, many follow the custom of R. Yehoshua b. Levi and recite these psalms to ward off harmful entities (see MA 239:2).³Berakhot 5a states: “R. Naḥman says: A Torah scholar recite Shema on his bed (for his learning protects him). Abaye says: Even a Torah scholar must recite one verse invoking God’s mercy, such as, ‘Into Your hand I entrust my spirit. You redeem me, Lord, God of truth’ (Tehilim 31:6).” Rif and Rosh mention that a Torah scholar is not obligated to repeat Shema, but Rambam and SA do not mention this, implying that according to them, a Torah scholar must also repeat it. Perhaps the source for their opinion is y. Berakhot 1:1, which discusses Torah scholars who recited Shema several times in order to fall asleep while saying Shema. Nevertheless, regarding the other verses, the recitation of which is not obligatory, it seems that a Torah scholar may opt to fall asleep while learning from a book or while deep in thought. However, Kaf Ha-ḥayim 239:1 states that by reciting Arizal’s formula for the bedtime Shema, one effects a tikun, and therefore even a Torah scholar must recite it.