Seeking Permission to enter (somebody’s House) and Manners relating to it

Imam Al-Nawawi’s Riyad-us-Saliheen
Chapter 140
Seeking Permission to enter (somebody’s House) and Manners relating to it

Allah, the Exalted, says:

“O you who believe! Enter not houses other than your own, until you have asked permission and greeted those in them.” (24:27)

“And when the children among you come to puberty, then let them (also) ask for permission, as those senior to them (in age).” (24:59)

870. Abu Musa Al-Ash`ari (May Allah be pleased with him) reported: The Messenger of Allah (sallallaahu ’alayhi wa sallam) said, “Permission is to be sought thrice. If it is accorded, you may enter; otherwise, go back.”
[Al-Bukhari and Muslim].

871. Sahl bin Sa`d (May Allah be pleased with him) reported: The Messenger of Allah (sallallaahu ’alayhi wa sallam) said, “Seeking permission to enter (somebody’s house) has been prescribed in order to restrain the eyes (from looking at something we are not supposed to look at).”
[Al-Bukhari and Muslim].

872. Rib`i bin Hirash (May Allah be pleased with him) reported: A man of Banu `Amir tribe has told us that he had asked the Prophet (sallallaahu ’alayhi wa sallam) for permission to enter when he was at home. He said: “May I enter?” Messenger of Allah (sallallaahu ’alayhi wa sallam) said to the servant, “Go out and instruct him about the manner of seeking permission. Tell him to say: As-Salamu `Alaikum (may you be safe from evil). May I come in?” The man heard this and said: “As-Salamu `Alaikum (may you be safe from evil). May I come in?” The Prophet (sallallaahu ’alayhi wa sallam) then accorded permission to him and he entered in.
[Abu Dawud].

873. Kildah bin Al-Hanbal (May Allah be pleased with him) reported: I visited the Prophet (sallallaahu ’alayhi wa sallam) and I entered his house without seeking permission. So he said, “Go back and say: `As-Salamu `alaikum (may you be safe from evil). May I come in?”’
[Abu Dawud and At-Tirmidhi].