Answer:
(And We said to him,˺ “Take in your hand a bundle of grass, and strike ˹your wife˺ with it, and do not break your oath.” We truly found him patient. What an excellent servant ˹he was˺! Indeed, he ˹constantly˺ turned ˹to Allah˺.) Sad 38:43
Job PBUH had a disagreement with his wife about something she did when he was ill, so he made an oath that when he got better he would beat her 100 lashes. It would have been an evil reward for her patience and all she tolerated for his sake when he was sick. So as not to break the oath he made, Allah told him to gather 100 straws and beat her lightly with them once. This was Allah’s mercy on his wife and him as Job PBUH was a faithful believer.
(وَخُذْ بِيَدِكَ ضِغْثًا فَاضْرِب بِّهِ وَلَا تَحْنَثْ ۗ إِنَّا وَجَدْنَاهُ صَابِرًا ۚ نِّعْمَ الْعَبْدُ ۖ إِنَّهُ أَوَّابٌ )
ص 38: 43
كَانَ أَيُّوبُ، عَلَيْهِ السَّلاَمُ، قَدْ غَضِبَ عَلَى زَوْجَتِهِ فِي شَيءٍ فَعَلْتَهُ وَهُوَ مَرِيضٌ، فَأَقْسَمَ إِنْ شَفَاهُ اللهُ تَعَالَى لَيَضْرِبَنَّهَا مِئَةَ جَلْدَةٍ، وَكَانَتْ زَوْجَتُهُ قَدْ أَخْلَصَتْ لَهُ، وَاحْتَمَلَتْ بَلاَءَهُ بِصَبْرٍ كَبِيرٍ فَكَانَ ضَرْبُها مَعَ كُلِّ مَا احْتَمَلَتْهُ جَزَاءً سَيِّئاً، فَأَفْتَاهُ اللهُ تَعَالَى أَنْ يَأْخُذَ بِيَدِهِ حُزْمَةً مِنَ العِيدَانِ فِيهَا مِئَةُ عُودٍ، وَيَضْرِبَها بِهَا ضَرْبَةً وَاحِدَةً، فَيَتَحَلَّلَ مِنْ يَمِينِهِ، وَلاَ يَحْنَثَ، فَرَحِمَهُ اللهُ بِهَذِهِ الفَتْوَى، وَرَحِمَ زَوْجَتَهُ الصَّابِرَةَ، فَقَدْ كَانَ أَيُّوبُ عَبْداً مُخْلِصاً للهِ، كَثِيرَ الإِنَابَةِ إِلَيْهِ.