In Islamic law, religious principles (uṣúl; lit. “roots”), concern the sources of the law that can be explicitly derived from the Qur’án and the Ḥadíth, whereas secondary laws and ordinances (furú‘ ; lit. “branches”) are deduced from the former through the discipline of jurisprudence (fiqh).
The “realm of subtle entities” (‘álam-i-dharr) is an allusion to the Covenant between God and Adam mentioned in Qur’án 7:172. In a Tablet ‘Abdu’l‑Bahá has written: “The realm of subtle entities that is alluded to referreth to the realities, specifications, individuations, capacities and potentialities of man in the mirror of the divine knowledge. As these potentialities and capacities differ, they each have their own particular exigency. That exigency consisteth in acquiescence and supplication.” (Má’idiy-i-Ásmání, vol. 2, (New Delhi: Bahá’í Publishing Trust, 1984), p. 30)