Tafsir of Ash-Shu`ara' 26:17

The particle an (أن) in the words of the Almighty, "That you send with us the Children of Israel," is explanatory (mufassirah), as the sending (al-irsal) understood from the term "messenger" (rasul) encompasses the meaning of speech. Abu Hayyan permitted it to be an infinitive particle (masdariyyah) with the meaning: "I am His messenger—Mighty and Majestic is He—with the command to send." This refers to releasing and letting go, as in your saying: "I released (arsaltu) the stone from my hand," or "The falcon was released (ursila)." The intended meaning is: let them go with us to Palestine, which was the dwelling place of both of them, peace be upon them. The Children of Israel had been enslaved for four hundred years, and their number at the time Moses, peace be upon him, was sent was six hundred and thirty thousand, according to what al-Baghawi mentioned.