What is the ruling on coercion to obedience, and is the one coerced rewarded for it? And what are the references that discussed the topic of coercion to truth?

Compulsion in truth (al-ikrah bi haqq) is the act of forcing a person to do what is obligatory upon them. It is permissible for someone in authority, such as a judge, to impose it, and its effects are then valid. Thus, a sale made under such compulsion is valid, a creditor is permitted to take their money, and zakat is waived for the one who refused to pay. The one compelled in truth is still morally obligated (mukallaf), but their action is not rewarded unless they intended it and performed it out of their own free choice.

Examples of this include compelling a disbeliever or apostate to embrace Islam, a father preventing his daughter from going out unveiled, compelling a son to pray, and compelling a procrastinator to pay zakat. The validity of these actions is clear externally, but internally, there is no reward for them except with intention and the purpose of complying with the Sharia. The negation of good from secret counsel (an-najwa) except in enjoining good, charity, and reconciling between people indicates that beneficial actions that extend to others are good, but there is no reward for them except with the seeking of Allah's pleasure.