This excerpt is taken from the book of Fazilat-ul-Sheikh Abdul Salam Rustami From Denial of Hadith to Denial of Quran.
Hadith 2: Musa (peace be upon him) slapping the Angel of Death
Reference: Sahih al-Bukhari, Ahadith al-Anbiya, Chapter on the Death of Musa, Hadith: 3407
Answer:
It is clearly present in this hadith that the Angel of Death came in human form and said to him (Musa, peace be upon him) that I have been sent to kill you. Musa (peace be upon him) did not recognize him (the Angel of Death) and slapped him. Obviously, if a person says that he has come to kill you, such treatment can be given to him, but when he came the second time, Musa (peace be upon him) recognized him and submitted humbly.
