Musannaf Ibn Abi Shayba 9:1082

Abu Khalid narrated to us, from Shu'bah, from Abu Bishr, from Tawus and Mujahid, they said: "The one in whose hand is the knot of marriage is the guardian (wali)." And Sa'id ibn Jubayr said: "It is the husband." So they spoke to him regarding that, and they did not depart until they followed Sa'id.