It may be helpful to change the order of these phrases. Alternate translation: "You who are from the fountain of Israel, praise Yahweh and bless God in the assembly"
The word "fountain" is a metaphor for the ability of the man Israel to be the ancestor of many people: as much water comes from a fountain, so Israel is the ancestor of many people. This also implies that the call is to those who serve God as the man Israel did. Alternate translation: "true descendants of Israel" or "all of you descendants from Israel"(See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/figs-explicit]])
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