A.T. Robertson Commentary Matthew 21:32

"For John came unto you in the way of righteousness, and ye believed him not; but the publicans and the harlots believed him: and ye, when ye saw it, did not even repent yourselves afterward, that ye might believe him." — Matthew 21:32 (ASV)

In the way of righteousness (εν οδω δικαιοσυνης). In the path of righteousness. Compare the two ways in Mt 7:13,14 and "the way of God" (22:16).