Theodoret of Cyrus
required everyone to take a solemn vow to remain steadfast in a manner of living aligned with the commandments, pledging to serve the one God who brings salvation.
And he went in to confirm as usual the covenant, that they should seek the Lord the God of their fathers with all their heart, and with all their soul.
וַיָּבֹ֣אוּ בַבְּרִ֔ית לִדְר֕וֹשׁ אֶת־יְהוָ֖ה אֱלֹהֵ֣י אֲבוֹתֵיהֶ֑ם בְּכָל־לְבָבָ֖ם וּבְכָל־נַפְשָֽׁם׃
One Church Father comments on this verse
required everyone to take a solemn vow to remain steadfast in a manner of living aligned with the commandments, pledging to serve the one God who brings salvation.
Passages read together with this verse.