I say, and with God's success: Obligation: it is the burden of the soul, and it has a real cause and an apparent cause: as for the real cause: it is the eternal address of God, Glorified and Exalted; because the one who imposes the rulings is God alone, but since His imposition is hidden from us and we cannot perceive it, He, Blessed and Exalted, has made for us apparent metaphorical causes to facilitate things for us, which are the times; as evidenced by the renewal of obligation with their renewal. As for the apparent cause: it is the time; as evidenced by its addition to it, which is a sign of causality: like the limit of adultery and the expiation for an oath. Refer to: Al-Maraqi p. 172, and the footnote of Al-Tahawi p. 173, and God knows best.