Sunan an-Nasa'i, Volume 1, Book 6, Hadith 614 (DarusSalam) ⓘ
It was narrated that Anas said: The Messenger of Allah said: "Whoever forgets a prayer, let him pray it when he remembers it."
أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا أَبُو عَوَانَةَ، عَنْ قَتَادَةَ، عَنْ أَنَسٍ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَنْ نَسِيَ صَلاَةً فَلْيُصَلِّهَا إِذَا ذَكَرَهَا " .
also referenced under: Book 6, Hadith 620 (In-Book)