Sahih Bukhari
Prophetic Commentary on the Quran (Tafseer of the Prophet (PBUH))
Volume: 006 / Book Number: 060 / Hadith Number: 39
Narrated Al-Bara:
In the Pre-lslamic Period when the people assumed Ihram, they would enter their houses from the back. So Allah revealed:--
"And it is not righteousness that you enter houses from the back, but the righteous man is he who fears Allah, obeys His Orders and keeps away from what He has forbidden. So enter houses through their doors." (2.189)