Abu Hurairah reported,
The Prophet of Allah Sulayman 
had sixty wives. He said, "Tonight I shall visit all my wives, and every one of them will conceive and give birth to a horseman who will fight in the cause of Allah." So he went around to his wives, but none of them bore a child except one woman, who gave birth to half a boy.The Prophet of Allah ﷺ said, "Had Sulayman said 'if Allah wills,' every one of them would have conceived and borne a horseman who would fight in the cause of Allah."
Azami 8465
Sahihعن أبي هريرة
أن نبي الله سليمان عليه السلام كان له ستون امرأة فقال: لأطوفن الليلة على نسائي فلتحملن كل امرأة ولتلدن فارسا يقاتل في سبيل الله فطاف على نسائه فما ولدت منهن إلا امرأة ولدت شق غلام قال نبي الله ﷺ: لو كان سليمان استثنى لحملت كل امرأة منهن فولدت فارسا يقاتل في سبيل الله.
Bukhari narrated it in Tawheed (7469), and Muslim in Oaths and Vows (1654:22), both through routes from Ayub Sakhtiyani, from Ibn Sirin, from Abu Hurairah, who mentioned it. The part attributed to the Prophet is the last portion. Mamar narrated it from Ayub with this same chain in similar wording, except that he narrated it with the phrase "a hundred women" and stopped the entire hadith at Abu Hurairah, as found in the tafsir of Abdul-Razzaq (1668). Hisham bin Hassan narrated it from Ibn Sirin from Abu Hurairah and said, "a hundred women," attributing the entire hadith, beginning and end, to the Prophet, as found with Imam Ahmad (7137, 10580) and Abu Awana (5994).The summary of what has come down in these hadiths regarding the number of Sulayman's wives ranges from sixty, seventy, ninety, ninety-nine, and a hundred. The most correct of these is "ninety," as Bukhari and other scholars have said, and it is the strongest in terms of chain of transmission. Other hadiths have been narrated with similar meaning containing numbers both higher and lower than this, but they are defective and none of them is sahih. Reconciling these numbers, the correct number is ninety, and the rest were concubines. Whoever said less than ninety was mistaken. Allah, the Exalted, knows best.As for his saying, "His companion said to him, 'Say, if Allah wills,' but he did not say, if Allah wills," this was due to forgetfulness on his part , because his mind was preoccupied with another matter and he did not notice, as has come explicitly in one of the routes of this hadith.