Supplication for Islam and the Muslims

اللَّهُمَّ أَعِزَّ الإِسْلَامَ وَالْمُسْلِمِينَ

Allāhumma aʿizza-l-Islāma wa-l-Muslimīna

O Allah, honour and strengthen Islam and the Muslims.

A general supplication, not a narration from the Prophet (peace be upon him).