What is the Shar'i (Islamic legal) opinion regarding a father's refusal to complete a marriage and his demand for divorce, despite the presence of a valid Islamic marriage contract and the husband's fulfillment of the conditions?

Since you have entered into a valid Islamic marriage contract with the woman, she has become your wife, and her guardian does not have the right to force you to divorce her. As for the condition of buying a house, if it was agreed upon, then it must be fulfilled. If you do not fulfill it within the specified period, they have the right to refer the matter to a judge to compel you to fulfill the condition or to annul the marriage. Before the period ends, they cannot request a divorce unless there is another valid reason, and you have the choice to refuse or agree, with or without compensation. It is advisable to involve righteous people to reach a solution, such as providing a rented dwelling, and to remind the woman's guardian of the benefit of ensuring the girl's chastity.