Gabriel
But if you conspire against him (Muhammad), then know that Allah is his ally, as are Gabriel, the righteous believers, and the angels, all his supporters.
66:4If ye twain turn unto Allah repentant, (ye have cause to do so) for your hearts desired (the ban); and if ye aid one another against him (Muhammad) then lo! Allah, even He, is his Protecting Friend, and Gabriel and the righteous among the believers; and furthermore the angels are his helpers.