Is a person to be blamed who sold land he had vowed for building a mosque, in order to pay off a debt he incurred to vouch for another person, and that after he had deposited part of the money with the creditor to avoid prosecution, and what should he do now?

If you vowed to donate a specific piece of land for the construction of a mosque, it is not permissible to sell it, as the right of the vow is attached to it. If it is sold, the land must be reclaimed, otherwise, you are obligated to guarantee it with the greater of its price and value, and purchase another land for the mosque. However, if you vowed to sell the land and spend its proceeds on building a mosque, its price remains your responsibility until you are able to do so, and expiation is not sufficient for you unless you despair of fulfilling it. The expiation for a vow is like the expiation for an oath: feeding ten poor persons, or clothing them, or freeing a slave; and if you cannot find [any of these], then fasting for three days.