Sunan an-Nasa'i
Book 6: The Book of the Times (of Prayer)
كتاب المواقيت
132 hadith in this book
Chapter 52 Concerning One Who Forgets A Prayer
باب فِيمَنْ نَسِيَ صَلاَةً
It was narrated that Anas said: The Messenger of Allah (ﷺ) 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 " .
Hadith text, translations and grading are courtesy of Sunnah.com.