It is permissible for a Muslim to pray as much as they wish after the ῾Ishā᾽ prayer with the intention of Qiyām al-Layl. In fact, the ῾Ishā᾽ prayer itself is considered a part of Qiyām al-Layl, based on the saying of the Prophet (peace be upon him) in the ḥadīth narrated by ῾Uthmān ibn ῾Affān who said: “I heard the Messenger of Allāh say: ‘Whoever prays ῾Ishā᾽ in congregation, it is as if he has prayed half the night. And whoever prays Fajr in congregation, it is as if he has prayed the entire night.'” [Narrated by Muslim].

Fatwa issued by Dr. Khālid Naṣr