From verse 13 to verse 24 of our chapter, we have the law with respect to birds. All of the carnivorous kind, that is, all that fed on flesh, were unclean; the omnivorous, or those who could eat any thing, were unclean; all those which though furnished with power to soar into the heavens would nevertheless grovel upon the earth were unclean. As to the latter class, there were some exceptional cases (ver. 21, 22.); but the general rule, the fixed principle, the standing ordinance, was as distinct as possible--"All fowls that creep, going upon all fours, shall be an abomination unto you." (Ver. 20.) All this is very simple in its instruction to us. Those fowls that could feed upon flesh, those that could swallow any thing or every thing, and all groveling fowls, were to be unclean to the Israel of God, because so pronounced by the God of Israel; nor can the spiritual mind have any difficulty in discerning the fitness of such an ordinance. We can not only trace in the habits of the above three classes of fowl the just ground of their being pronounced unclean, but we can also see in them the striking exhibition of that in nature which is to be strenuously guarded against by every true Christian. Such an one is called to refuse every thing of a carnal nature. Moreover, he cannot feed promiscuously upon every thing that comes before him. He must "try the things that differ;" he must "take heed what he hears;" he must exercise a discerning mind, a spiritual judgment, a heavenly taste. Finally, he must use his wings; he must rise on the pinions of faith, and find his place in the celestial sphere to which he belongs. In short, there must be nothing groveling, nothing promiscuous, nothing unclean, for the Christian.
As to "creeping things," the following was the general rule: "And every creeping thing that creepeth upon the earth shall be an abomination; it shall not be eaten." (Ver. 41.) How wonderful to think of the condescending grace of Jehovah! He could stoop to give directions about a crawling reptile. He would not leave His people at a loss as to the most trivial affair. The priest's guide-book contained the most ample instructions as to every thing. He desired to keep His people free from the defilement consequent upon touching, tasting, or handling aught that was unclean. They were not their own, and hence they were not to do as they pleased. They belonged to Jehovah; His name was called upon them; they were identified with Him. His Word was to be their grand regulating standard in every case. From it they were to learn the ceremonial _status_ of beasts, birds, fishes, and creeping things. They were not to think their own thoughts, to exercise their own reasoning powers, or be guided by their own imaginations in such matters. _God's Word was to be their sole directory._ Other nations might eat what they pleased, but Israel enjoyed the high privilege of eating that only which was pleasing to Jehovah.
Nor was it as to the mere matter of _eating_ aught that was unclean that the people of God were so jealously guarded. Bare _contact_ was forbidden. (See ver. 8, 24, 26-28, 31-41.) It was impossible for a member of the Israel of God to touch that which was unclean without contracting defilement. This is a principle largely unfolded both in the law and the prophets.--"Thus saith the Lord of hosts, 'Ask ye now the priests concerning the law, saying, If one bear holy flesh in the skirt of his garment, and with his skirt do touch bread, or pottage, or wine, or oil, or any meat, shall it be holy?' And the priests answered and said, 'No.' Then said Haggai, 'If one that is unclean by a dead body _touch_ any of these, shall it be unclean?' And the priests answered and said, 'It shall be unclean.'" (Hag. ii. 11-13.) Jehovah would have His people holy in all things. They were neither to eat nor touch aught that was unclean.--"Ye shall not make yourselves abominable with any creeping thing that creepeth, neither shall ye make yourselves unclean with them, that ye should be defiled thereby." Then follows the powerful reason for all this careful separation.--"_For I am the Lord your God_: ye shall therefore sanctify yourselves, and ye shall be holy; _for I am holy_: neither shall ye defile yourselves with any manner of creeping thing that creepeth upon the earth. For I am the Lord that bringeth you up out of the land of Egypt, to be _your God_: ye shall therefore be holy, _for I am holy_." (Ver. 43-45.)