Surah 13. Ar-Ra'd, Ayah 36

Sc., "and who believe in it".

I.e., while admitting that the Qur'an contains much that coincides with the spiritual concepts taught by their own religions. The designation ahzab (lit., "parties" or "sects", sing. hizb) connotes here the followers of other religions or creeds (Tabari and Razi).

I.e., because it offers them guidance in this world and holds out to them the promise of ultimate happiness in the life to come.

The particle "only" (innama) at the beginning of this sentence "clearly shows that there is [in Islam] no obligation, no ordinance and no prohibition that is not connected with this [principle]" (Razi).

The Book: in a general sense, Revelation. "Those to whom the Book hath been given" are both (1) the People of the Book of previous revelations, who study the new Revelation in Arabic without prejudice and find in it confirmation of what their ancestors had received and believed in it, and (2) the Muslims who receive the Qur-an with such joy.

Ahzab (plural of hizb = parties, sects, troops, clans. The reference may be to the clans mentioned in xxx. 20 and 22 (that whole Sura is called Ahzab). But we can understand it in a perfectly general sense. Among all sections of the people there are persons who would receive a portion of Allah's truth but reject whatever does not suit them or fall in with their selfish aims or vain desires. The proper answer to them is: Surely, Allah's command is universal,-to worship and serve Him and refuse to bend the knee to any other; the man of God finds his staff and support in it; but he must invite all to share in its blessings; it came from Allah, and to Allah shall we all return.