What was the reason for the revelation of the two noble verses: "And he presents for Us an example and forgets his [own] creation. He says, 'Who will give life to bones while they are disintegrated?' (78) Say, 'He will give them life who produced them the first time; and He is, of all creation, Knowing.' (79)"?

As-Suyuti mentioned in "Ad-Durr Al-Manthur" several narrations regarding the reason for the revelation of the verse. The soundest of them is what Al-Hakim and others narrated from Ibn Abbas (may Allah be pleased with both of them), who said: Al-As ibn Wa'il came to the Messenger of Allah (peace be upon him) with a decayed bone. He crumbled it with his hand and said: "O Muhammad, will Allah bring this back to life after what I see?" The Prophet (peace be upon him) said: "Yes, Allah will raise this, then cause you to die, then bring you back to life, then admit you into the Fire of Hell." So the verses from the end of Surah (definition) Yasin were revealed: "Does not man see that We have created him from a sperm-drop; then behold, he is an open disputer" to the end of the Surah.