The Messenger of Allah, peace and blessings be upon him, said: Cut the mustaches and leave the beards, and oppose the polytheists. The Almighty says.
وَمَا آتَاكُمُ الرَّسُولُ فَخُذُوهُ وَمَا نَهَاكُمْ عَنْهُ فَانْتَهُوا [الحشر:7].
And whatever the Messenger has given you - take; and what he has forbidden you - refrain from.[Al-hashr 7]From this it is also known that exempting the mustache is one of the sins and one of the disobedience of the disobedience.This is how shaving the beard and shortening it is among the sins and disobedience that diminish and weaken faith.