«طَمَعْ أَبْلِيسْ فِي الجَنَّهْ»

The saying is applied to a person whose desire is set on something that can never be obtained. Iblis, the Devil, was cast out of Paradise for good, so his craving to get back in stands for a wish with no chance of fulfilment.

Beyond naming an impossible aim, the phrase passes judgment on the one who holds it. It casts the hope as wishful, perhaps presumptuous, and signals that the speaker sees no real path from the longing to the thing longed for.

Use it as a pointed remark about someone who keeps longing for or chasing a goal that is plainly out of reach. It can mock open ambition or gently deflate a hope that the speaker considers wholly unrealistic.