Muwatta Malik: Hajj — Ibn al-Musayyab say, “Anyone that does umra in Shawwal, Dhu’l-Qada or Dhu… (Hadith No. 766)

Yahya related to me from Malik that Yahya ibn Said used to hear Said ibn al-Musayyab say, "Anyone that does umra in Shawwal, Dhu'l-Qada or Dhu l-Hijja, and then stays in Makka until it is time for the hajj, is doing tamattu if he then does hajj. He must sacrifice whatever animal it is easy for him to obtain, and if he cannot find one then he must fast three days during hajj and seven days when he returns

Explanation:

Reference: Muwatta Malik: Hajj, Hadith No. 766