9:81
فَرِحَ ٱلْمُخَلَّفُونَ بِمَقْعَدِهِمْ خِلَـٰفَ رَسُولِ ٱللَّهِ وَكَرِهُوٓا۟ أَن يُجَـٰهِدُوا۟ بِأَمْوَٰلِهِمْ وَأَنفُسِهِمْ فِى سَبِيلِ ٱللَّهِ وَقَالُوا۟ لَا تَنفِرُوا۟ فِى ٱلْحَرِّ ۗ قُلْ نَارُ جَهَنَّمَ أَشَدُّ حَرًّا ۚ لَّوْ كَانُوا۟ يَفْقَهُونَ
9:81
Those who were left behind boasted for sitting back against [the command of] the Apostle of Allah, and were reluctant to wage jihad with their possessions and persons in the way of Allah, and they said, ‘Do not go forth in this heat.’ Say, The fire of hell is severer in heat, should they understand. - Ali Quli Qarai (English)