Compare the marginal references. In other kinds of labor the oxen were usually muzzled. When driven to and fro over the threshing-floor in order to stamp out the grain from the chaff, they were to be allowed to partake of the fruits of their labors.

Thou shalt not muzzle the ox, etc. - In Judea, as well as in Egypt, Greece, and Italy, they make use of beeves to tread out the corn; and Dr. Shaw tells us that the people of Barbary continue to tread out their corn after the custom of the East. Instead of beeves they frequently made use of mules and horses, by tying by the neck three or four in like manner together, and whipping them afterwards round about the nedders, as they call the treading floors, (the Libycae areae Hor), where the sheaves lie open and expanded, in the same manner as they are placed and prepared with us for threshing. This indeed is a much quicker way than ours, though less cleanly, for as it is performed in the open air, (Hosea 13:3), upon any round level plot of ground, daubed over with cow's dung to prevent as much as possible the earth, sand, or gravel from rising; a great quantity of them all, notwithstanding this precaution, must unavoidably be taken up with the grain, at the same time that the straw, which is their chief and only fodder, is hereby shattered to pieces; a circumstance very pertinently alluded to in 2 Kings 13:7, where the king of Syria is said to have made the Israelites like the dust by threshing - Travels, p. 138. While the oxen were at work some muzzled their mouths to hinder them from eating the corn, which Moses here forbids, instructing the people by this symbolical precept to be kind to their servants and laborers, but especially to those who ministered to them in holy things; so St. Paul applies it 1 Corinthians 9:9, etc.; 1 Timothy 5:18. Le Clerc considers the injunction as wholly symbolical; and perhaps in this view it was intended to confirm the laws enjoined in the fourteenth and fifteenth verses of the former chapter. See Dodd and Shaw.

In Bengal, where the same mode of treading cut the corn is used, some muzzle the ox, and others do not, according to the disposition of the farmer - Ward.

Thou shall not muzzle the ox when he treadeth out the corn. As oxen are used in ploughing, so likewise in treading or beating out the corn; of the manner of which; see Gill on 1 Corinthians 9:9; now while it was thus employed, it might not be restrained by any means from eating the corn as it had an opportunity, either by a muzzle put over its mouth, or other ways. The Gentiles had several ways of restraining their cattle from eating, while they thus made use of them, to which this law is opposed. Maimonides (f) has collected several or them together, as prohibited by it; as putting a thorn into its mouth, causing a lion to lie down by it, or causing its calf to lie down without, or spreading a skin on the top of the corn, that so it may not eat. Aelianus (g) relates a very particular way of hindering oxen from eating at such times, used some countries, which was this; that oxen might not eat of the ears of corn, in a floor where they were trod out, they used to besmear their nostrils with cows' dung, which was so disagreeable to the creature, that it would not taste anything though pressed with famine. This law is not to be limited to the ox only, or to this peculiar work assigned it; but, as Jarchi says, respects any sort of cattle, and whatsoever work that has food in it, none of them being to be restrained from eating while at work: and this law was not made for the creatures only, but for men also; and especially for the sake of ministers of the word; who for their strength, labour, and industry, are compared to oxen, and ought to be comfortably supported and maintained on account of their work; for the illustration and confirmation of which this passage is twice produced; see Gill on 1 Corinthians 9:9; See Gill on 1 Corinthians 9:10; See Gill on 1 Timothy 5:17; See Gill on 1 Timothy 5:18.

(f) Hilchot Shecirut, c. 13. sect. 2, 3.((g) Hist. Animal. l. 4. c. 25.

The command not to put a muzzle upon the ox when threshing, is no doubt proverbial in its nature, and even in the context before us is not intended to apply merely literally to an ox employed in threshing, but to be understood in the general sense in which the Apostle Paul uses it in 1 Corinthians 9:9 and 1 Timothy 5:18, viz., that a labourer was not to be deprived of his wages. As the mode of threshing presupposed here - namely, with oxen yoked together, and driven to and fro over the corn that had been strewn upon the floor, that they might kick out the grains with their hoofs - has been retained to the present day in the East, so has also the custom of leaving the animals employed in threshing without a muzzle (vid., Hoest, Marokos, p. 129; Wellst. Arabien, i. p. 194; Robinson, Pal. ii. pp. 206-7, iii. p. 6), although the Mosaic injunctions are not so strictly observed by the Christians as by the Mohammedans (Robinson, ii. p. 207).

Thou shalt not muzzle the ox when he treadeth out the corn.

25:4 He treadeth out the corn - Which they did in those parts, either immediately by their hoofs on by drawing carts or other instruments over the corn. Hereby God taught them humanity, even to their beasts that served them, and much more to their servants or other men who laboured for them, especially to their ministers, 1Cor 9:9.

treadeth...: Heb. thresheth

4. Thou shalt not muzzle the ox when he treadeth out the corn-In Judea, as in modern Syria and Egypt, the larger grains were beaten out by the feet of oxen, which, yoked together, day after day trod round the wide open spaces which form the threshing-floors. The animals were allowed freely to pick up a mouthful, when they chose to do so: a wise as well as humane regulation, introduced by the law of Moses (compare 1Co 9:9; 1Ti 5:17, 18).

25:4 This is a charge to husbandmen. It teaches us to make much of the animals that serve us. But we must learn, not only to be just, but kind to all who are employed for the good of our better part, our souls, 1Co 9:9.