What is the ruling on reading the Qur’an when overcome by drowsiness and lacking humility (khushu’)?

If drowsiness does not prevent one from understanding what is being said and allows for reading, then there is no harm in reciting the prescribed remembrances (adhkar) before sleeping. Devotion (khushu') is not a condition for the permissibility of recitation, but rather one of its recommended etiquettes. Weak hadiths have been reported regarding the virtue of reciting Surat ad-Dukhan and al-Waqi'ah. As for Surat al-Mulk and as-Sajdah, their recitation before sleeping is sunnah, in addition to the prescribed remembrances.