Making up a missed prayer. And it is recommended to hasten to make it up
وَحَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، حَدَّثَنَا عَبْدُ الأَعْلَى، حَدَّثَنَا سَعِيدٌ، عَنْ قَتَادَةَ، عَنْ أَنَسِ بْنِ مَالِكٍ، قَالَ قَالَ نَبِيُّ اللَّهِ صلى الله عليه وسلم " مَنْ نَسِيَ صَلاَةً أَوْ نَامَ عَنْهَا فَكَفَّارَتُهَا أَنْ يُصَلِّيَهَا إِذَا ذَكَرَهَا " .
Qatada narrated on the authority of Anas b. Malik that the Messenger of Allah (ﷺ) said: He who forgets the prayer, or he slept (and it was omitted), its expiation is (only) that he should observe it when he remembers it.