Why did Gabriel ask the Prophet (PBUH) to "recite" during their first encounter, instead of telling him to "say," even though he did not give him a book or a manuscript?

The meaning of "Iqra'" (read) in Arabic comes in two forms: the first is reading from written text, and the second is reading from memory (reciting from what is memorized). Allah Almighty commanded His Prophet, peace and blessings be upon him, in the verse "Recite in the name of your Lord," to recite from memory, not from a written scroll, as Jibreel (Gabriel) cast upon him the beginning of Surat Al-Alaq for him to memorize and recite. The Prophet, peace and blessings be upon him, replied, "I am not a reader," because he was unlettered and did not read from books. So, the reading here was a recitation of what was cast upon him.