Musannaf Ibn Abi Shaybah

Hasan did not allow a guardian by will (wasi) to give permission for marriage, except if the one appointing the wasi says, "You are the guardian (wasi) for the marriages of my sisters and my daughters." If he does so, then the wasi is more entitled than the wali (legal guardian) in the matter of marriage. If this is not said, then the wali is more entitled than the wasi.