The hadeeth is authentic. The angel startled Musa, peace be upon him by appearing like this and he was in the form of a human being. Therefore,  Mosa defended himself and smacked him!

Found In: Sahih Bukhari Chapter No: 23, Funerals (Al-Janaaiz) Hadith no: 423 Narrated: Abu Hurairah (radhiy Allahu anhu) The angel of death was sent to Moses and when he went to him, Moses slapped him severely, spoiling one of his eyes. The angel went back to his Lord,.. the hadith goes on..heard its an authentic hadith..but why did a messenger of Allah indulge in such an action?

Commentary on Hadeeth | March 21, 2015 3:23 pm
Previous

One maulana in the masjid gave a daleel of sahih Muslim saying Jabir Bin Abdullah (radiy Allahu anhu) narrates that the Prophet (Salla Allahu alaihi wa sallam) once entered the masjid and told us why is that I am seeing you raising your hands like that of a horses tail, make sure you have sukoon in salaah. And then the maulana said this daleel is against rafayaain. can you please explain this?
Next

Is this hadith Sahih that when the Prophet (salla Allahu alaihi wa sallam) used to do miswak a sound like “Kha khaah” would come from his mouth?