Ambiyaa

Hazrat Moosa (alaihis salaam) asking Allah Ta'ala why He gave Imaan to few people

Q: I have heard many times a narration where Moosa (alaihis salaam) asked Allah Ta'ala why he gave imaan to a few people and not all. Allah Ta'ala told him to go into a garden and choose a flower. He chose the best flower so Allah Ta'ala said that He chose Imaan for who He loved the most.

Could you tell me if this is authentic?

False allegation against Hazrat Aadam (alaihis salaam)

Q: I was reading Stories of the Prophet by ibn Kathir, I think it was Adam AS, I think I read an ayah in which I think it was mentioned that when Adam AS followed shaytan and ate the fruit of the forbidden tree, he was not on Islamic monotheism (I think it was in brackets but I’m not sure). But when I read it again I couldn’t find it, I thought maybe I misread something. Does this ayah appear in the Quran? If yes what does it mean by not on true monotheism?