Sahih al-Bukhari 3424
صحيح البخاري#3424SahihNarrated 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 Solomon (ﷺ) 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)
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 60:96