Sahih Muslim Book - 27, Hadith - 4289

وَحَدَّثَنِى زُهَيْرُ بْنُ حَرْبٍ حَدَّثَنَا شَبَابَةُ حَدَّثَنِى وَرْقَاءُ عَنْ أَبِى الزِّنَادِ عَنِ الأَعْرَجِ عَنْ أَبِى هُرَيْرَةَ عَنِ النَّبِىِّ -صلى الله عليه وسلم- قَالَ « قَالَ سُلَيْمَانُ بْنُ دَاوُدَ لأَطُوفَنَّ اللَّيْلَةَ عَلَى تِسْعِينَ امْرَأَةً كُلُّهَا تَأْتِى بِفَارِسٍ يُقَاتِلُ فِى سَبِيلِ اللَّهِ. فَقَالَ لَهُ صَاحِبُهُ قُلْ إِنْ شَاءَ اللَّهُ. فَلَمْ يَقُلْ إِنْ شَاءَ اللَّهُ. فَطَافَ عَلَيْهِنَّ جَمِيعًا فَلَمْ تَحْمِلْ مِنْهُنَّ إِلاَّ امْرَأَةٌ وَاحِدَةٌ فَجَاءَتْ بِشِقِّ رَجُلٍ وَايْمُ الَّذِى نَفْسُ مُحَمَّدٍ بِيَدِهِ لَوْ قَالَ إِنْ شَاءَ اللَّهُ. لَجَاهَدُوا فِى سَبِيلِ اللَّهِ فُرْسَانًا أَجْمَعُونَ ».

It was narrated from Abu Hurairah that the Prophet (s.a.w) said: "Sulaiman bin Dawud said: 'Tonight I will go around to ninety women, and each of them will give birth to a knight who will fight in the cause of Allah.' His companion said to him: 'Say "If Allah wills.'" But he did not say 'If Allah wills,' and he went round to all of them. None of them became pregnant except one woman, who gave birth to a deformed child. By the One in Whose Hand is the soul of Muhammad, if he had said 'If Allah wills,' they would all have been knights, striving in the cause of Allah.''