Radak: Yisrael, if they guard the Mishpatim that He commanded, they are fortunate. When they do His will, He does much good for them. And even when they rebel, He bears them for a long time - perhaps they will repent. All the more so if they would guard His Mishpatim and do Tzedakah constantly, He would do Tzedakah with them, and they would never be exiled from their land.

Malbim: They are those who guard Mitzvos Bein Adam l'Chavero.

Radak: Yisrael sometimes do good, but mostly their deeds are bad. They will be fortunate if they will always do good.

Malbim: Tzedakah refers to Mitzvos Bein Adam la'Makom. Hashem's Chasadim are always good; everything depends on the recipient's preparation. Eretz Yisrael was given to them on condition that they guard His Chukim and Mitzvos. If they do, they will have good and happiness always. There is no difference between earlier eras and later; Hashem's Chasadim do not change. Those who guard His Torah are happy also nowadays!