Surah 9. Al-Tawba, Ayah 108

Lit., "in it" - sc., "to pray therein".

Lit., "Indeed, a house of worship founded...upon God-consciousness (taqwa) is most deserving...", etc. Some of the commentators believe that this is a reference to the mosque founded by the Prophet at Quba', a village close to Medina, on his arrival there in the month of Rabi' al-Awwal in the year 1 H., since it was the first mosque ever built by him or his followers. There are, however, authentic Traditions to the effect that the Prophet applied the designation of "a house of worship founded on God-consciousness" to his (later-built) mosque at Medina as well (Muslim, Tirmidhi, Nasa'i, Ibn Hanbal). It is, therefore, reasonable to assume that it applies to every mosque sincerely dedicated by its founders to the worship of God: a view which is supported by the next verse.

 See footnote for 7:46.

The original "Mosque of Piety" built by the Holy Prophet himself.

The true Muslim must be pure in body, mind, and heart. His motives should always be sincere, and his religion without any alloy of worldy gain.