They reap every one his corn - Margin, "mingled corn," or "dredge." The word used here (בליל belı̂yl) denotes, properly, "meslin," mixed provender, made up of various kinds of grain, as of barley, vetches, etc., prepared for cattle; see the notes at Isaiah 30:24.
In the field - They break in upon the fields of others, and rob them of their grain, instead of cultivating the earth themselves. So it is rendered by Jerome - Agrum non suum deme-runt; et vineam ejus, quem vi. oppresserint vindemiant. The Septuagint renders it, "A field, not their own, they reap down before the time - πρὸ ὥρας pro hōras.
They gather the vintage of the wicked - Margin, "the wicked gather the vintage." Rather, they gather the vintage of the oppressor. It is not the vintage of honest industry; not a harvest which is the result of their own labor, but of plunder. They live by depredations on others. This is descriptive of those who support themselves by robbery.

They reap every one his corn in the field - This is perfectly characteristic. These wandering hordes often make sudden irruptions, and carry off the harvest of grain, olives, vines, etc., and plunge with it into the wilderness, where none can follow them. The Chaldee gives the same sense: "They reap in a field that is not their own, and cut off the vineyard of the wicked."

They reap [every one] (f) his corn in the field: and they gather the (g) vintage of the wicked.
(f) Meaning the poor man's.
(g) Signifying that one wicked man will not spoil another, but for necessity.

They reap everyone his corn in the field,.... Not the poor, who are obliged to reap the corn of the wicked for them without any wages, as some; but rather the wicked reap the corn of the poor; they are so insolent and impudent, that they do not take the corn out of their barns by stealth, but while it is standing in the field; they come openly and reap it down, as if it was their own, without any fear of God or men: it is observed, that the word (k) signifies a mixture of the poorer sorts of corn, which is scarce anything better than food for cattle; yet this they cut down and carry off, as forage for their horses and asses at least. Some of the ancient versions, taking it to be two words, render them, "which is not their own" (l); they go into a field that is not theirs, and reap corn that do not belong to them, that they have no right unto, and so are guilty of great injustice, and of doing injury to others:
and they gather the vintage of the wicked; gather the grapes off of the vines of wicked men, which are gathered, as the word signifies, at the latter end of the year, in autumn; and though they belong to wicked men like themselves, yet they spare them not, but seize on all that come to hand, whether the property of good men or bad men; and thus sometimes one wicked man is an instrument of punishing another: or "the wicked gather the vintage" (m); that is, of the poor; as they reap where they have not sown, they gather of that they have not planted.
(k) "migma suum", Bolducius; "farraginem ejus vel suam", Tigurine version, Junius & Tremellius, Piscator, Cocceius, Michaelis. (l) Sept. "non suum", V. L. so the Targum, and Aben Ezra, Grotius, Codurcus. (m) "et in vinea (aliena) vindemiant impii", Tigurine version; "vineasque vindemiant impii", Castalio.

Like the wild asses (Job 24:5) they (these Bedouin robbers) reap (metaphorically) their various grain (so the Hebrew for "corn" means). The wild ass does not let man pile his mixed provender up in a stable (Isaiah 30:24); so these robbers find their food in the open air, at one time in the desert (Job 24:5), at another in the fields.
the vintage of the wicked--Hebrew, "the wicked gather the vintage"; the vintage of robbery, not of honest industry. If we translate "belonging to the wicked," then it will imply that the wicked alone have vineyards, the "pious poor" (Job 24:4) have none. "Gather" in Hebrew, is "gather late." As the first clause refers to the early harvest of corn, so the second to the vintage late in autumn.

They - The oppressors. Wicked - Of such as themselves: so they promiscuously robbed all, even their brethren in iniquity.