The Prophet ﷺ said: When one of you inflicts a beating, he should avoid striking the face. (Using translation from Abū Dāʾūd 4493)   

عَنِ النَّبِيِّ ﷺ قَالَ «إِذَا ضَرَبَ أَحَدُكُمْ فَلْيَجْتَنِبِ الْوَجْهَ»