Tafsir of Al-Quraish 106:3

Verse [ 106:3] فَلْيَعْبُدُوا رَ‌بَّ هَـٰذَا الْبَيْتِ (they must worship the Lord of this House.) Having mentioned the Divine favors, the Quraish are especially enjoined to express their gratitude to 'the Lord of this House'. Here, out of many attributes of Allah, 'the Lord of this House' is singled out, because it was this House that became the source and fountain of all blessings for them.