Ahmad ibn Muhammad ibn ‘Isa, from al-Hasan ibn Ali ibn Yaqtin, from his brother al-Husayn, from Ali ibn Yaqtin, who said: I asked Abu al-Hasan عليه السلام, peace be upon him, about a man who misses the ‘witr’ prayer at night. Imam عليه السلام said: "He should make it up as ‘witr’ whenever he remembers, even if the sun has passed its zenith."