Al-Kāfi - Volume 5 > Woman Lawful in Marriage for the Holy Prophet
Hadith #6

6- عَلِيُّ بْنُ إِبْرَاهِيمَ عَنْ أَبِيهِ عَنِ ابْنِ أَبِي عُمَيْرٍ عَنْ حَمَّادٍ عَنِ الْحَلَبِيِّ عَنْ أَبِي عَبْدِ اللهِ (عَلَيْهِ السَّلام) أَنَّ رَسُولَ اللهِ (صَلَّى اللهُ عَلَيْهِ وَآلِه) لَمْ يَتَزَوَّجْ عَلَى خَدِيجَةَ.

6. Ali ibn Ibrahim has narrated from his father from ibn abu ‘ Umayr from Hammad from al-Halabiy who has said the following: “Abu ‘Abd Allah, ‘Alayhi al-Salam, has said, ‘The Messenger of Allah, O Allah, grant compensation to Muhammad and his family worthy of their services to Your cause, did not marry a second wife in Khadijah’s lifetime.’”