Jamieson, Fausset and Brown on Matthew 23:23

23. Woe unto you, scribes and Pharisees, hypocrites! for ye pay tithe of mint and anise--rather, "dill," as in Margin.

and cummin--In Luke (Lu 11:42) it is "and rue, and all manner of herbs." They grounded this practice on Le 27:30, which they interpreted rigidly. Our Lord purposely names the most trifling products of the earth as examples of what they punctiliously exacted the tenth of.

and have omitted the weightier matters of the law, judgment, mercy, and faith--In Luke (Lu 11:42) it is "judgment, mercy, and the love of God"--the expression being probably varied by our Lord Himself on the two different occasions. In both His reference is to Mi 6:6-8, where the prophet makes all acceptable religion to consist of three elements--"doing justly, loving mercy, and walking humbly with our God"; which third element presupposes and comprehends both the "faith" of Matthew and the "love" of Luke. See on Mr 12:29; Mr 12:32, 33. The same tendency to merge greater duties in less besets even the children of God; but it is the characteristic of hypocrites.

these ought ye to have done, and not to leave the other undone--There is no need for one set of duties to jostle out another; but it is to be carefully noted that of the greater duties our Lord says, "Ye ought to have done" them, while of the lesser He merely says, "Ye ought not to leave them undone."