Sahih Muslim – Hadith No : 4801

The (foregoing) tradition has also been narrated on the authority of Hatim through the same chain of transmitters with the difference that according to this version both these types of expeditions were seven in number.

Hadith In Arabic Text :

وحدثنا قتيبة بن سعيد، حدثنا حاتم، بهذا الإسناد ‏.‏ غير أنه قال في كلتيهما سبع غزوات ‏.‏

Chapter : The Book of Jihad and Expedition – كتاب الجهاد والسير