Al-Fath 48:4

هُوَ ٱلَّذِيٓ أَنزَلَ ٱلسَّكِينَةَ فِي قُلُوبِ ٱلۡمُؤۡمِنِينَ لِيَزۡدَادُوٓاْ إِيمَٰنٗا مَّعَ إِيمَٰنِهِمۡۗ وَلِلَّهِ جُنُودُ ٱلسَّمَٰوَٰتِ وَٱلۡأَرۡضِۚ وَكَانَ ٱللَّهُ عَلِيمًا حَكِيمٗا 4

It is He who sent down tranquillity into the hearts of the believers that they would increase in faith along with their [present] faith. And to Allah belong the soldiers of the heavens and the earth, and ever is Allah Knowing and Wise