Is it permissible to recite the morning and evening adhkar and Surat Al-Mulk before sleeping without raising one's voice, or (reciting them) in the heart?

It is not sufficient for the morning, evening, and sleep adhkar (remembrances) to merely pass them through the heart; rather, they must be uttered verbally. The majority of scholars hold that a sound must be produced, audible to the speaker themselves, while the Malikis deem it sufficient to move the tongue. Silent dhikr (remembrance) is superior to vocal dhikr because it is further removed from showing off (riya'). Nevertheless, passing the adhkar through the heart without verbalization is permissible and rewarded, especially when verbal dhikr is difficult, such as when relieving oneself or during marital intimacy.