Tafsir of Al-Mu'minoon 23:113

They deemed the duration of their stay short in relation to what they realized of the length of their eternity in the Fire. It is said: They deemed it short because those were days of their pleasure in contrast to what they are in now, and days of pleasure are short. It is also said: It is because those days had passed, and what has passed is not regarded; thus, its length or brevity is not known, so one assumes it was short.

Meaning: Those capable of counting. For we, due to the torment that has overwhelmed us, are unable to do so. Or, it refers to the angels who count the deeds of the servants, as narrated by a group from Mujahid.

Al-Hasan and al-Kisa’i (in one narration) read "al-‘ādīn" with a light dal, meaning: the oppressors. For they would say just as we say; the followers used to call the leaders by this name because they wronged them by leading them astray.

It was also read as "al-‘ādīyīn" with a stressed ya, the plural of ‘ādī, attributed to the people of ‘Ad. The intended meaning is those who live long lives, for the people of ‘Ad used to live for a long time. That is: Ask the ancients who lived long lives, for they too deem the duration of their stay to be short.