I say, and with God's success: The obligation of performance is the request to discharge the debt, and it has a real cause and an apparent cause: As for the real cause: it is the address of God Almighty: that is, His request from us. And as for the apparent cause: it is the word indicating that: like the word: (Establish the prayer). See: Tahthawi's margin, p. 173, and God knows best.