Qur'an 66:4

إِن تَتُوبَآ إِلَى ٱللَّهِ فَقَدْ صَغَتْ قُلُوبُكُمَا ۖ وَإِن تَظَـٰهَرَا عَلَيْهِ فَإِنَّ ٱللَّهَ هُوَ مَوْلَىٰهُ وَجِبْرِيلُ وَصَـٰلِحُ ٱلْمُؤْمِنِينَ ۖ وَٱلْمَلَـٰٓئِكَةُ بَعْدَ ذَٰلِكَ ظَهِيرٌ

If 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.