Assalaamo alaykum. I have heard that Iblees (the devil) lost hope in Allah's Mercy when Nooh (Noah), may Allah exalt his mention, told him to bow to Adam's, may Allah exalt his mention, grave and he refused. Is that true? When did Iblees lose hope in Allah's mercy? May Allah reward you.

All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallahu ʻalayhi wa sallam, is His slave and Messenger.

Perhaps the question refers to the story cited by some Tafseer (Quran exegesis) scholars and attributed to Abu Al-ʻAaliyah. It was cited by As-Suyooti in his book Ad-Durr Al-Manthoor, Ath-Thaʻlabi in his Tafseer book, and others. Its wording is as follows:

“Ibn Abi Ad-Dunya and Ibn ʻAsaakir narrated in Makaayid Ash-Shaytaan on the authority of Abu Al-ʻAaliyah that he said: When the ark of Nooh (Noah), may Allah exalt his mention, landed, he saw Iblees on the rear end of the ship, so he said to him, ‘Woe be to you! The people of the earth drowned because of you!’ Iblees said, ‘What do I do?’ Nooh said, ‘You repent.’ Iblees said, ‘Ask your Lord if repentance is possible for me?’ Nooh supplicated his Lord, so He revealed to him that his repentance was to prostrate before the grave of Aadam (Adam). Nooh said to Iblees, ‘There is repentance for you.” He asked, ‘What is it?’ Nooh said, ‘That you prostrate before Aadam’s grave.’ Iblees said, ‘I refused to prostrate before him while he was alive; would I prostrate before him while he is dead!’”

This story is false and inauthentic. In Mukhtasar Al-Fataawa Al-Misriyyah, Badr Ad-Deen Abu ʻAbdullah ibn Muhammad ibn ʻAli Al-Hanbali Al-Baʻli said, “Some scholars cited the narration that Iblees was asked to prostrate before the grave of Aadam. As for asking him to do that in the Hereafter, I do not know of anyone who mentioned it. In fact, both stories are false.”

Allah knows best.