en_tn_lite_do_not_use/psa/081/004.md

For it

Here "it" refers to the feast day.

a decree given by the God of Jacob

This can be stated in active form. Alternate translation: "the God of Jacob decreed it" or "the God of Jacob commanded it" (See: rc://en/ta/man/translate/figs-activepassive)

the God of Jacob

Here "Jacob" represents all of his descendants. Alternate translation: "the God of Israel, the nation of Jacob's descendants" (See: rc://en/ta/man/translate/figs-synecdoche)