What is the ruling regarding my daughter's engagement without my knowledge and consent, knowing that I am her guardian, and I had previously rejected the suitor?

The prevailing tendency of a father is to be keen on his daughter's welfare. Some jurists have stated that a father is not deemed to be preventing (his daughter from marrying) if he rejects a suitor at first instance. This is due to the inherent affection and compassion a father has for his daughter. Perhaps the father knows something about her condition or the suitor's condition that is not suitable.

Therefore, you are not preventing (her marriage) by refusing your daughter's engagement to this man. The daughter and her mother have erred by agreeing to the engagement despite your refusal. Our advice to you is to handle the matter wisely. If the man is pleasing in his religiosity and character, and you hope there is a benefit in her marriage to him, then marry her to him.