Is it permissible to supplicate while sleeping, walking, or engaged in any work, such as sewing a garment?

A person who is sleepy or drowsy should stop supplicating until the drowsiness leaves them, for fear that they might supplicate against themselves. As for supplicating while walking or engaging in work, it is permissible. Remembrance (dhikr) is prescribed in all states, but one should strive for presence of heart during supplication, because Allah does not answer the supplication of a heedless, inattentive heart.