The Master told His disciples not to give what is “holy” to dogs. In this context, “what is holy” refers to the sacrifices offered in the Temple. When He said, “Do not give what is holy to dogs,” He was citing a well-known rule about how to handle the “holy” portions from Temple sacrifice. It is not appropriate to give meats from the LORD’s altar to dogs. The Talmud agrees, “We may not use the meat of animals dedicated for sacrifices to feed the dogs.”
Yeshua cited that Levitical rule to make a different point. He wanted to warn His disciples against teaching Torah (what is holy) to idolaters:
Do not give what is holy to dogs, and do not throw your pearls before swine, or they will trample them under their feet, and turn and tear you to pieces. (Matthew 7:6)
The adages and interpretations of the rabbis are figuratively called “pearls.” Moreover, in the terminology of rabbinic discourse, “dog” can be idiomatic for a gentile idolater and a “pig” implies a Roman.
The sages were also reluctant to teach Gentiles the secrets of Torah:
A treasure must not be revealed to everyone, so also with the precious words of Torah. One must not go into the deeper meaning of them, except in the presence of those individuals who are suitably trained. (y.Avodah Zarah 41d)
Rabbi Ammi said, “The teachings of the Torah are not to be transmitted to an idolater, for it is said [in Psalm 147:20], “He has not dealt thus with any nation; and as for His ordinances, they have not known them.” (b.Chagigah 15a)
Rabbi Hillel used to say, “If you see a generation that does not cherish the Torah, hold in your words.” It does no good to preach Bible at atheists; it only provokes them. Likewise, the Master cautioned his disciples about idolaters and Romans who would reject the message and might likely be provoked to violence by it.
In a similar passage, Yeshua warned His disciples, “Do not go in the way of the Gentiles, and do not enter any city of the Samaritans; but rather go to the lost sheep of the house of Israel” (Matthew 10:5-6). In Matthew 15:26, He objected to healing a Gentile woman’s daughter, saying, “It is not good to take the children’s bread and throw it to the dogs” (Matthew 15:26). On a practical level, we should understand Yeshua’s words to be a prohibition against forcing the message of the kingdom on people who do not want to hear it.
The “dog” and “pig” terminology certainly sounds offensive, particularly the to the ears of a Gentile Yeshua-follower today, but Yeshua’s cautions about teaching the Gentiles need to be weighed in balance with His positive interaction with the Roman centurion in Matthew 8:5-13, His act of kindness for the Syrian woman in Matthew 15, and ultimately, His commission to the disciples before His ascension. He said, “All authority has been given to Me in heaven and on earth. Go therefore and make disciples of all the nations” (Matthew 28:18-19).