"The Messenger of Allah (ﷺ) was asked about a man who slept and missed the prayer, or forgot it. He said: 'The expiation for that is to pray it when he remembers it.'"
Sunan an-Nasa'i Book 6, Hadith 121
← Previous Hadith The Messenger of Allah (ﷺ) said: "Whoever forgets a prayer, let him pray it when he remembers it."

Sunan an-Nasa'i Book 6, Hadith 120 Next Hadith → "They told the Prophet (ﷺ) that they had slept and missed the prayer. He said: 'There is no negligence when one sleeps, rather negligence is when one is awake. If any one of you forgets a prayer or sleeps and misses it, let him pray it when he remembers it.'"

Sunan an-Nasa'i Book 6, Hadith 122