Musannaf Ibn Abi Shaybah 3450 — What a man says on entering the mosque

Sayyiduna Abu Hurayrah (may Allah be pleased with him) said: Sayyiduna Ka'b bin Ujrah (may Allah be pleased with him) said to me: "When you enter the mosque, send salutations of peace upon the Prophet (peace and blessings be upon him), then say: 'O Allah, open for me the doors of Your mercy.' And when you go out of the mosque, send salutations of peace upon the Prophet (peace and blessings be upon him) and say these words: 'O Allah, protect me from Satan.'"