en_tn/psa/089/002.md

Covenant faithfulness has been established forever

God always doing what he promised to do is spoken of as if his faithfulness were a building that God has built and made firm. This can be stated in active form. Alternate translation: "You will always be faithful because of your covenant with us" (See: rc://en/ta/man/translate/figs-metaphor and rc://en/ta/man/translate/figs-activepassive)

your truthfulness you have established in the heavens

God always doing what he promised to do is spoken of as if his faithfulness were a building that God has built and made firm. (See: rc://en/ta/man/translate/figs-metaphor)

in the heavens

These words could refer to 1) God's dwelling place, meaning that God rules from heaven and he always does what he promises, or 2) the sky, meaning that God's promises are as constant and permanent as the sky .