Those who remained behind rejoiced in their staying [at home] after [the (9:81)

﴿فَرِحَ الْمُخَلَّفُونَ بِمَقْعَدِهِمْ خِلَافَ رَسُولِ اللَّهِ وَكَرِهُوا أَن يُجَاهِدُوا بِأَمْوَالِهِمْ وَأَنفُسِهِمْ فِي سَبِيلِ اللَّهِ وَقَالُوا لَا تَنفِرُوا فِي الْحَرِّ ۗ قُلْ نَارُ جَهَنَّمَ أَشَدُّ حَرًّا ۚ لَّوْ كَانُوا يَفْقَهُونَ﴾
[ التوبة: 81]

9:81 Those who remained behind rejoiced in their staying [at home] after [the departure of] the Messenger of Allah and disliked to strive with their wealth and their lives in the cause of Allah and said, "Do not go forth in the heat." Say, "The fire of Hell is more intensive in heat" - if they would but understand.

Those hypocrites who failed to join the battle of Tabūk were happy not to strive in Allah’s path, in opposition to the Messenger of Allah.
They were reluctant to strive with their wealth and live in Allah’s path as the believers did.
They said to their fellow hypocrites, in order to keep them behind, ‘Do not march in the heat!’ The battle of Tabūk was during the hot season.
Say to them, O Messenger: The fire of Hell that awaits the hypocrites is much hotter than this heat that they are running away from, if they only knew.

Those who stayed away (from Tabuk expedition) rejoiced in their staying behind the Messenger of Allah; they hated to strive and fight with their properties and their lives in the Cause of Allah, and they said: "March not forth in the heat." Say: "The Fire of Hell is more intense in heat", if only they could understand!

phonetic Transliteration

Fariha almukhallafoona bimaqAAadihim khilafa rasooli Allahi wakarihoo an yujahidoo biamwalihim waanfusihim fee sabeeli Allahi waqaloo la tanfiroo fee alharri qul naru jahannama ashaddu harran law kanoo yafqahoona

Abdullah Yusuf Ali - Translation

Those who were left behind (in the Tabuk expedition) rejoiced in their inaction behind the back of the Messenger of Allah: they hated to strive and fight, with their goods and their persons, in the cause of Allah: they said, "Go not forth in the heat." Say, "The fire of Hell is fiercer in heat." If only they could understand!

Safi-ur-Rahman al-Mubarakpuri

Those who stayed away (from Tabuk expedition) rejoiced in their staying behind the Messenger of Allah; they hated to strive and fight with their properties and their lives in the cause of Allah, and they said: "March not forth in the heat." Say: "The fire of Hell is more intense in heat;" if only they could understand!

Page 200 English transliteration