Sunnah of Entering & Leaving the House (Part 1)

Dua for entering the house:

‘ Allahumma Innee Asaluka Khairaha WaKhairama Jabaltaha ‘Alaihe Wa A-‘oodhu Bika Min Shirriha Wa Sharrima Jabaltaha ‘Alaihe ’

Meaning:
‘O Allah I ask you the blessing of entering the home and the blessing of leaving. In the name Allah, we leave and enter the house, and upon Allah, Our Sustainers, we rely and depend’  (Abu Dawood)

Ask permission before entering:
The Islamic code of seeking permission specifies that one should stand close to the door, (knock) and thereafter say "Assalaamualaikum Warhmatullahi", may I come in?

Hazrat Abu Muas Ash-Ari (R.A) narrates that Holy Prophet (S.A.W) said, “Ask permission three times, if you get permission of entry, then it is acceptable, if not then return.”  (Bukhari & Muslim)

Don't enter anyone’s house or room without permission. You are required to seek their permission first. Make Salaam:

Our beloved Prophet (S.A.W) said, “When you enter the house make Salaam to those in the house, and when leave the home make Salaam”.

From poverty to wealth:
Hazrat Sahal bin S’ad (R.A) stated that a person came to the Holy Prophet (S.A.W) and complained about poverty.

The Prophet (S.A.W) said, “When you enter your house make Salaam and enter, whether it is empty or occupied, then send me Salaam, and finally recite Surah Ikhlas (‘Qulhuwallahh Ahad’) once”.

This person did exactly as Holy Prophet (S.A.W) had advised him and he became so wealthy that he helped his relatives and friends.     (Tafseer-e-Qurtubi)