ENOfficial
He reported God’s Messenger as saying, “When any of you fights he must avoid the face, for God created Adam in His own image.” (Bukhari and Muslim.)
Source: sunnah.com
Other translations
Arabic
وَعَنْهُ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «إِذَا قَاتَلَ أَحَدُكُمْ فَلْيَجْتَنِبِ الْوَجْهَ فَإِنَّ اللَّهَ خَلَقَ آدَمَ عَلَى صُورَتِهِ»
sunnah.com