A.T. Robertson Commentary Galatians 4:21

"Tell me, ye that desire to be under the law, do ye not hear the law?" — Galatians 4:21 (ASV)

That desire to be under the law (ο υπο νομον θελοντες εινα). "Under law" (no article), as in 3:23; 4:4, legalistic system. Paul views them as on the point of surrender to legalism, as "wanting" (θελοντες) to do it (1:6; 3:3; 4:11,17). Paul makes direct reference to these so disposed to "hear the law." He makes a surprising turn, but a legitimate one for the legalists by an allegorical use of Scripture.