COMMENTARY on 17:9
A. Yusuf Ali:

Translation:
Verily this Qur´an do guide to that which is most right (or stable), 2183 and giveth the Glad Tidings to the Believers who work deeds of righteousness, that they shall have a magnificent reward;
Commentary:

2183  The instability and crookedness of the Jewish soul having been mentioned, the healing balm which should have cured it is now pointed out. The Message of the Qur'an is for all. Those who have Faith and show that Faith in their conduct must reap their spiritual reward. But those who reject Faith cannot escape punishment. Apart from what is past, apart from questions of national or racial history, there is a spiritual Hope-and a spiritual Danger—for every soul.

 

Muhammad Asad:

Translation:
VERILY, this Qur'an shows the way to all that is most upright, 10 and gives the believers who do good deeds the glad tiding that theirs will be a great reward;
Commentary:
10  I.e., conformable to ethical rectitude and beneficial to man's individual and social life. Thus, after showing that sinning is synonymous with denying the truth, the discourse returns to the fundamental theme 9f the Qur'an, already alluded to in verse 2 of this surah: namely, the statement that God always offers guidance to man through the revelations which He bestows upon His prophets.