Is it forbidden or permissible for a father to raise the deferred dower (sadaq) for his daughter, knowing that the suitor is religious and of good character?

If the intent is the father's exorbitant demand for the dowry, then that is not appropriate; for Islam dislikes exaggeration in dowries, and a low dowry is considered a blessing for the woman and a blessed marriage. The guidance of the Prophet (peace be upon him) and his companions was to facilitate dowries. Therefore, it is advisable to abandon exaggeration if the suitor is a man of good character and religious commitment.

However, if the marriage has taken place and the two parties have agreed upon a specific dowry and deferred dowry, then the father has the right to demand it on behalf of his daughter if she authorizes him or if it is customary to do so, as the dowry is an exclusive right of the woman. The husband is obligated to fulfill it when it becomes due and he is solvent, as Allah Almighty says: "O you who have believed, fulfill [your] contracts," and the Prophet (peace be upon him) said: "The conditions most worthy of fulfillment are those by which you make intimacy lawful." If the husband is in straitened circumstances, he must be granted a respite.