Al-Husayn ibn Sa'id narrated from Ibn Abi Umayr from Umar ibn Udhaynah from Zurarah: Abu Ja'far, peace be upon him, was asked about a man who prayed without purification, or forgot prayers and did not perform them, or slept through them. Imam عليه السلام said: "He must make them up whenever he remembers them, at whatever time he remembers, by night or by day. If the time of a present prayer comes and he has not yet finished making up what he missed, then he should make up what he can without fearing that the time of the present prayer will expire. The present prayer has greater right to its time, so he should perform it first. When he has prayed it, he should then complete whatever he had missed from before. And he should not perform even a single rak'ah of supererogatory prayer until he has made up the obligatory prayer."