The Quran

۞ وَلَو أَرادُوا الخُروجَ لَأَعَدّوا لَهُ عُدَّةً وَلٰكِن كَرِهَ اللَّهُ انبِعاثَهُم فَثَبَّطَهُم وَقيلَ اقعُدوا مَعَ القاعِدينَ

Muhammad Asad

For, had they been [truly] desirous of setting out [with thee], they would surely have made some preparation therefor: but God was averse to their taking the field, and so He caused them to hold back when it was said, "[You may] stay at home with all [the others] who stay at home."¹

This may refer to the permission granted by the Prophet (see verse 43) to certain of his followers who, for apparently legitimate reasons, were unable to take part in the campaign (Tabari, Zamakhshari, Razi) - a permission of which the hypocrites only too readily availed themselves. As regards God's "causing" those hypocrites to sin in this way, see 2:7 and the corresponding note 7, as well as surah 3, note 117.