(55) باب قَضَاءِ الصَّلاَةِ الْفَائِتَةِ وَاسْتِحْبَابِ تَعْجِيلِ قَضَائِهَا
Qatada reported from Anas b. Malik that the Messenger of Allah (ﷺ) said:
He who forgets the prayer should say it when he remembers it, there is no explation for it, except this. Qatada said: (Allah says)" And observe prayer for remembrance of Me"
Reference: Sahih Muslim 684 a
In-book reference: Book 5, Hadith 402
USC-MSA web (English) reference(deprecated numbering scheme): Book 4, Hadith 1454