I. This is one of those verses which show most clearly and graciously the forethought of our heavenly Teacher, in providing for us the Old Testament: (1) in that words spoken on a particular occasion to the Jews are made to convey a heavenly warning and message to Christians of all generations at all times; (2) in that Almighty God here, as in many other places, furnishes comfort and instruction beforehand to that bitterest of cares and doubts, the care and doubt which must hang over those who feel that they have grieved His Spirit, received in baptism, by wilful sin, and having been partakers of the heavenly gift, have fallen away and trodden Christ, His grace, His warnings, His example, under foot.
II. "Wherein shall we return?" Instead of submitting at once to God's reproof, the Jews of Malachi's time make answer, and pretend to argue the matter with Him; they go on as if they did not understand what was said, as if their conscience did not smite them at all. The reply in the text, "Wherein shall we return?" may be taken in the like sense, as if they who were reproved were not aware of any particular reason why they should be called to repentance. Or it may be understood in a milder and better meaning, as spoken by a person really in doubt, wishing to repent, but hardly knowing how to begin. Either way, it is a manner of speaking and thinking which one meets with every day in our times. For the benefit of both sorts of answerers, God's wisdom has condescended to point out, by what follows in the prophet, the right course to be pursued. The particular sin which he here reproves in them is their robbing God of His tithes; and when they say, "Wherein shall we return?" this is His Divine command, "Bring all the tithes into the storehouse, that there may be meat in Mine house," etc. That is, Make a courageous effort and force yourself to do those things which are most contrary to the particular sins against which conscience warns you. Do not stand waiting and hesitating, and asking how you must set about the work of repentance, but at once begin exercising yourself in whatever most contradicts the bad tendencies which you cannot help being aware of. Only let us begin courageously and at once, and persevere humbly and patiently; for the journey is great for us, the time is short, and we, alas! are far behind.
Plain Sermons by Contributors to "Tracts for the Times" vol. iv., p. 311.
References: Malachi 3:7. M. Dix, Sermons Doctrinal and Practical,p. 286; Preacher's Monthly,vol. viii., p. 176; Plain Sermons by Contributors to "Tracts for the Times," vol. x., p. 231; J. Keble, Sermons for Christmas to Epiphany,p. 236.