We sent it/him down

Indeed, We sent it/him down during the Night of Decree.

[Qur'aan 97:1]

The pronoun "it/him" in this Verse refers to the Qur'aan.

al-'aluusi has related that there is an Ijmaa on this.

And he said that there is a weak opinion that it refers to Jibriil but this opinion is not to be considered.

Reference(s)
al-haawi fii tafsiir al-Qur'aan al-Kariim
Volume 16 Page 370