"Sulaiman said: 'I will certainly go around to ninety women tonight, each of whom will bear a child who will fight in the cause of Allah.' It was said to him: 'Say: If Allah wills' but he did not say it. He went around to them but none of them bore a child except for one woman who bore half a person." The Messenger of Allah said: "If he had said: 'If Allah wills,' he would not have broken his vow, and this would have been a means to help him to get what he wanted." (Using translation from Nasāʾī 3856)
قَالَ رَسُولُ اللهِ ﷺ قَالَ سُلَيْمَانُ بْنُ دَاوُدَ لَأَطُوفَنَّ اللَّيْلَةَ بِمِائَةِ امْرَأَةٍ تَلِدُ كُلُّ امْرَأَةٍ مِنْهُنَّ غُلَامًا يُقَاتِلُ فِي سَبِيلِ اللهِ قَالَ وَنَسِيَ أَنْ يَقُولَ إِنْ شَاءَ اللهُ فَأَطَافَ بِهِنَّ قَالَ فَلَمْ تَلِدْ مِنْهُنَّ امْرَأَةٌ إِلَّا وَاحِدَةٌ نِصْفَ إِنْسَانٍ فَقَالَ رَسُولُ اللهِ ﷺ لَوْ قَالَ إِنْ شَاءَ اللهُ لَمْ يَحْنَثْ وَكَانَ دَرَكًا لِحَاجَتِهِ