أَنْزَلَهَا عَلَى أَنْبِيَائِهِ
He revealed them to His prophets.
Revelation identifies the source of the message: God, while a prophet receives and conveys it. The expression does not require interpreting revelation as the physical displacement of a material object.
It does not follow that every prophet received a separate written book in exactly the same form. The central point is that God bestowed scripture upon prophets and communicated guidance through them. The source of revelation differs from its mode of communication.