(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).'" (IT)
Reference (IT): Sunan an-Nasa'i 729 (IT)
In-book reference (IT): Book 8, Hadith 42 (IT)
English translation (IT): Vol. 1, Book 8, Hadith 730 (IT)