(36) باب الْقَوْلِ عِنْدَ دُخُولِ الْمَسْجِدِ وَعِنْدَ الْخُرُوجِ مِنْهُ
It was narrated that 'Abdul-Malik bin Sa'eed said:
"I heard Abu Humaid and Abu Usaid say: 'The Messenger of Allah (ﷺ) said: "When any one of you enters the Masjid, let him say: 'Allahumma aftahli abwaba rahmatik (O Allah, open to me the gates of your mercy). And when he leaves let him say: Allahumma inni as'aluka min fadlik (O Allah, I ask You of Your bounty).'" (DE)
Reference (DE): Sunan an-Nasa'i 729 (DE)
In-book reference (DE): Book 8, Hadith 42 (DE)
English translation (DE): Vol. 1, Book 8, Hadith 730 (DE)