Sunan an-Nasā'ī 613✓ 5Sahih
أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا أَبُو عَوَانَةَ، عَنْ قَتَادَةَ، عَنْ أَنَسٍ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَنْ نَسِيَ صَلاَةً فَلْيُصَلِّهَا إِذَا ذَكَرَهَا " .
It was narrated that Anas said: The Messenger of Allah (ﷺ) said: "Whoever forgets a prayer, let him pray it when he remembers it