Is a promise of marriage or wearing an engagement ring considered marriage before the marriage contract is concluded, and what is the ruling on authorizing the girl to conclude her marriage contract with the suitor?

A woman does not become lawful for a man except after a valid, Sharia-compliant marriage contract, which is not concluded by a mere promise or the wearing of a ring. For its validity, it requires the guardian (wali), witnesses, offer (ijab), and acceptance (qabul).

A man appointing another to accept the marriage on his behalf is permissible. However, scholars differ regarding a woman appointing another: the Malikis permit it, while the Shafi'is hold that it is not permissible.

Therefore, it is recommended to appoint a man to accept the marriage in order to avoid scholarly dispute.

It is worth noting that wearing an engagement ring has no basis in Islamic law.