Allāh’s Messenger (May Allāh praise him and Peace be upon him) legislated that when somebody forgets something in his prayer, he is to prostrate twice to make up for it. The ruling on this is that it is obligatory because the Prophet (May Allāh praise him and Peace be upon him) ordered us to do it when he said ,“When you are in doubt about whether you have performed an element of your prayer, make every effort to work out and establish what you have prayed and complete your prayer based on that. Then do the Salām. Then prostrate twice.” [Al Fatāwā: 23/28].

• It was narrated from ‘Abdullāh Ibn Mas’ūd (May Allah be pleased with him) that he said, “As long as you are in prayer, you are knocking on the King’s door, and the King’s door is opened for whoever knocks on it.” [Ḥilyatu Al Awliyā`].