Narrated Abu Huraira:

The Prophet (ﷺ) said, "Solomon (the son of) David said, 'Tonight I will sleep with seventy ladies each of whom will conceive a child who will be a knight fighting for "Allah's Cause.' His companion said, 'If Allah will.' But Solomon did not say so; therefore none of those women got pregnant except one who gave birth to a half child." The Prophet (ﷺ) further said, "If the Prophet (ﷺ) Solomon had said it (i.e. 'If Allah will') he would have begotten children who would have fought in Allah's Cause." Shuaib and Ibn Abi Az-Zinad said, "Ninety (women) is more correct (than seventy).

حَدَّثَنَا خَالِدُ بْنُ مَخْلَدٍ، حَدَّثَنَا مُغِيرَةُ بْنُ عَبْدِ الرَّحْمَنِ، عَنْ أَبِي الزِّنَادِ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ ‏"‏ قَالَ سُلَيْمَانُ بْنُ دَاوُدَ لأَطُوفَنَّ اللَّيْلَةَ عَلَى سَبْعِينَ امْرَأَةً تَحْمِلُ كُلُّ امْرَأَةٍ فَارِسًا يُجَاهِدُ فِي سَبِيلِ اللَّهِ، فَقَالَ لَهُ صَاحِبُهُ إِنْ شَاءَ اللَّهُ‏.‏ فَلَمْ يَقُلْ، وَلَمْ تَحْمِلْ شَيْئًا إِلاَّ وَاحِدًا سَاقِطًا إِحْدَى شِقَّيْهِ ‏"‏‏.‏ فَقَالَ النَّبِيُّ صلى الله عليه وسلم ‏"‏ لَوْ قَالَهَا لَجَاهَدُوا فِي سَبِيلِ اللَّهِ ‏"‏‏.‏ قَالَ شُعَيْبٌ وَابْنُ أَبِي الزِّنَادِ ‏"‏ تِسْعِينَ ‏"‏‏.‏ وَهْوَ أَصَحُّ‏.‏