Tafsir of Yunus 10:9

{Their Lord guides them by their faith} He directs them, by virtue of their faith, to remain steadfast on the path that leads to reward. For this reason, He made {rivers flowing beneath them} an explanation and interpretation of it, because holding fast to the cause of happiness is like attaining it.

It is also possible that He means: He guides them in the Hereafter by the light of their faith to the path of Paradise, as in His saying: {On the day you see the believing men and believing women, their light proceeding before them and on their right} (Al-Hadid: 12). From this is the Hadith: (When the believer emerges from his grave, his deeds are fashioned for him in a beautiful form, and it says to him: "I am your deeds," and it becomes a light and a guide for him to Paradise. As for the disbeliever, when he emerges from his grave, his deeds are fashioned for him in an ugly form, and it says to him: "I am your deeds," and it leads him until it casts him into the Fire.)

If you ask: This verse indicates that the faith for which a servant deserves guidance, success, and light on the Day of Resurrection is a qualified faith—that is, faith accompanied by righteous deeds. As for faith not accompanied by righteous deeds, its possessor has neither success nor light.

I say: That is indeed the case. Do you not see how He made the connection [in the verse] a combination of faith and action? It is as if He said: "Those who combined faith and righteous deeds," then said: {by their faith}, meaning: by this faith to which righteous deeds are joined. This is a clear matter with no ambiguity.

{Their call} Their supplication, for "O Allah" (Allahumma) is a call to Allah, and its meaning is: "O Allah, we glorify You," just as the one who performs the Qunut says in his supplication: "O Allah, You alone we worship, and to You we pray and prostrate."

It is also possible that "call" means worship, as in: {And I will withdraw from you and that which you call upon other than Allah} (Maryam: 48). This is based on the meaning that there is no obligation or worship in Paradise; their worship is nothing but glorifying and praising Allah. That is not [a burdensome] worship; rather, they are inspired to do it and speak it out of pleasure without effort, as in His saying: {And their prayer at the House was not but whistling and handclapping} (Al-Anfal: 35).

{Their call therein} The conclusion of their call, which is glorification, is that they say: {Praise be to Allah, Lord of the worlds}.

{Their greeting therein is "Peace"} This means that they greet one another with "Peace." It is also said: It is the greeting of the angels to them (attributing the verbal noun to the object). It is also said: It is Allah’s greeting to them.

The word {that} (an) is the lightened form of the heavy [particle] anna, and its origin is annahu (that it is), with the pronoun referring to the state of affairs, as in the verse: That he is ruined, he who walks barefoot and wears sandals. It has also been recited as anna al-hamdu lillah (with the shaddah and the accusative case for al-hamd).

{And if Allah were to hasten for the people the evil as they hasten the good, their term would have been decreed for them. But We leave those who do not expect the meeting with Us to wander blindly in their transgression.}