en_tn/isa/63/07.md

I will tell of the acts of Yahweh's covenant faithfulness

The abstract noun "faithfulness" can be stated as "faithfully" or "faithful." See how you translated "covenant faithfulness" in Isaiah 16:5. Alternate translation: "I will tell about how God has acted faithfully to his covenant" or "I will tell about all the faithful things God has done for his people" (See: rc://en/ta/man/jit/figs-abstractnouns)

I will tell

Here "I" refers to Isaiah.

done for us

Here "us" refers to Isaiah and the people of Israel. (See: rc://en/ta/man/jit/figs-exclusive)