Assalaamu alaykum. It is my habit to recite Surah As-Sajdah and drink milk at night before sleeping. In Surah As-Sajdah, there is a prostration, so am I supposed to do the prostration given that I recite this surah every day?

All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallahu ʻalayhi wa sallam, is His slave and Messenger.

The majority of the scholars held that the recitation prostration is an act of the Sunnah and that the conditions for its validity are the same as the conditions for the validity of the voluntary prayer; namely: being in a state of ritual purity, concealing the ʻAwrah (what should be covered of the body), and facing the prayer direction.

Accordingly, it is a Sunnah that you perform the prostration upon reciting a verse that requires that provided that the conditions mentioned above are met, even if you recite it every night. But if you do not perform that prostration while its conditions are met, then you bear no sin for that because it is not obligatory.

Allah knows best.