en_tn/rom/04/11.md

a seal of the righteousness that he had by faith while he was still uncircumcised

Here "righteousness that he had by faith" means that God considered him to be righteous because he had faith. Alternate translation: "a visible sign that God considered him righteous because he had believed in God before he was circumcised" (See: rc://en/ta/man/translate/figs-explicit)

so that righteousness would be counted to them

You can translate this in an active form. Alternate translation: "so that God would consider them righteous" (See: rc://en/ta/man/translate/figs-activepassive)