Paul here quotes Deuteronomy 27:26. This verse explains the curse Israel would experience if they did not follow all of God's commands in their covenant with him (see Deuteronomy 27:9–26; compare Deuteronomy 28:15–68; 31:26; Joshua 1:8; Malachi 2:2; see also Genesis 3:14–19; 4:10–12). Sinful humans cannot fully obey God's will (see Romans 3:9–20).