Surah 28. Al-Qasas, Ayah 51

Lit., "We have caused this word to reach them gradually": this meaning is implied in the verbal form wassalna, which - like the grammatically identical form nazzalna - points to the gradual, step-by-step revelation of the Qur'an during the twenty-three years of Muhammad's prophetic ministry.

Before this the Quraish might have said that the Word of Allah had come to the Hebrews in their tongue or in Greek, which was used by the Hebrews in the time of Jesus. Now that Word is brought to their own doors, in their own Arabic tongue, by a man of their own race and family. Surely they have no excuse now for remaining strangers to the higher moral and spiritual law.