Concise Quran Commentary
Whomever Allah wishes to guide to the right path, He opens their heart to Islam so they accept it willingly. Whomever He wishes to abandon and not guide, He makes their chest extremely narrow and unable to accept the truth, such that they become like a person climbing into the higher layers of the atmosphere while finding it increasingly difficult to breathe. Just as Allah made this extreme narrowness the condition of the person who goes astray, He will place the punishment on those who do not have faith in Him.