"The Messenger of Allah said: 'Whoever swears an oath and says: "If Allah wills, then he has made an exception."'"  

قَالَ رَسُولُ اللَّهِ ﷺ مَنْ حَلَفَ عَلَى يَمِينٍ فَقَالَ إِنْ شَاءَ اللَّهُ فَقَدِ اسْتَثْنَى  

"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."  

سُلَيْمَانُ لأَطُوفَنَّ اللَّيْلَةَ عَلَى تِسْعِينَ امْرَأَةً تَلِدُ كُلُّ امْرَأَةٍ مِنْهُنَّ غُلاَمًا يُقَاتِلُ فِي سَبِيلِ اللَّهِ فَقِيلَ لَهُ قُلْ إِنْ شَاءَ اللَّهُ فَلَمْ يَقُلْ فَطَافَ بِهِنَّ فَلَمْ تَلِدْ مِنْهُنَّ إِلاَّ امْرَأَةٌ وَاحِدَةٌ نِصْفَ إِنْسَانٍ فَقَالَ رَسُولُ اللَّهِ ﷺ لَوْ قَالَ إِنْ شَاءَ اللَّهُ لَمْ يَحْنَثْ وَكَانَ دَرَكًا لِحَاجَتِهِ