Tafsir of Fussilat 41:49

Man is fickle when Ease comes to Him after Difficulty Allah says,

ﻻ يسٲم اﻻنسان من دعاء الخير وإن مسه الشر

Man does not get tired of asking for good; but if an evil touches him, Allah tells us that man never gets bored of asking his Lord for good things, such as wealth, physical health, etc., but if evil touches him -- i.e., trials and difficulties or poverty --

فيووس قنوط

then he gives up all hope and is lost in despair, i.e., he thinks that he will never experience anything good again