Mosques and Places of Prayerكتاب الْمَسَاجِدِ وَمَوَاضِعِ الصَّلاَةِ
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