en_tn/psa/100/005.md

his covenant faithfulness endures forever

The abstract noun "faithfulness" can be translated with an adjective. AT: "he is faithful to his covenant forever" (See: rc://en/ta/man/translate/figs-abstractnouns)

his truthfulness through all generations

The verb may be supplied from the previous phrase. The abstract noun "truthfulness" can be translated with an adjective. AT: "his truthfulness endures through all generations" or "he is truthful through all generations" (See: rc://en/ta/man/translate/figs-ellipsis and rc://en/ta/man/translate/figs-abstractnouns)

through all generations

"generation after generation." See how this is translated in Psalms 89:4.