Perhaps, it is based on this congruity that it was said in verse 11 that man would, on occasions, pray for something in a haste, something that spells out destruction for him. If Allah Ta` ala were to answer such a prayer, he would be ruined. But, Allah Ta’ ala does not answer such prayers instantly until man himself comes to realize that his prayer was made in error and that it was fatal for him. Then, in the last sentence of this very verse, a natural weakness of man has been mentioned in the form of a standing rule - that man is, by nature, haste-prone. He keeps his sight trained on passing profit and loss and falls short on foresight and hindsight. He loves to go for the immediate gain and comfort, even if it happens to be only a little. He would not bat an eye to prefer it to the greater and more lasting gain and comfort. In short, this verse points out to a natural weakness of human beings in general.
And some authorities in Tafsir have taken this verse to be related to a particular event. The event they refer to concerns Nadr ibn Harith who had made a prayer in the heat of his hostility to Islam saying:
اللھُمَّ اِن کَانَ ھٰذَا ھوُالحَقَّ مِن عندِکَ فَاَمطِر عَلَینَا حِجارَۃً مَّنَ السَّمَآِء اَوأتنا بِعَذَاب اَلِیم
O Allah, if this [ Islam ] is the truth from You, then, rain down on us rocks from the skies or send upon us some other painful punishment.
In that case, 'al-insan' of the text would be referring to those mentioned above, or those like them.