One of Jesus’ more difficult teachings is in Matt. 7:6:

“Do not give dogs what is sacred; do not throw your pearls to pigs. If you do, they may trample them under their feet, and then turn and tear you to pieces.”

Jesus here describes a person cornered by enraged dogs and swine. In desperation and fright, the person throws to the animals their most precious possession, a bag full of pearls. The animals believe it to be food, but finding them inedible, they trample them underfoot, and tear the person to pieces.

However, Jesus is not simply talking about animals, but a certain kind of person. In the Bible, people who are recognized to be without value are called dogs or swine (See 1 Sam. 17:43; 2 Sam. 16:9; 2 Kgs. 8:13; 2 Pet. 2:18-22). Jesus teaches to not waste time with those who reject the Word of God (our pearls), for not only will they reject the Word, but you also.

It’s a sad reality, but there are some people who reject the wisdom of God’s word. God’s wisdom to us is to get out of their way, because if they don’t have respect for God and his Word, they won’t have any for those who reveal his Word. Jesus teaches to be prudent in whom we teach if we don’t want to be the victim of such people.
Solomon explains why: Prov. 1:7 and 15:21 say that “fools despise wisdom and discipline,” and that “A mocker resents correction; he will not consult the wise.”

So, then, “Do not speak to a fool, for he will scorn the wisdom of your words.” (Prov. 23:9). As Jesus, Solomon recommends a discriminatory attitude towards the ones we try to teach: “Whoever corrects a mocker invites insult; whoever rebukes a wicked man incurs abuse. Do not rebuke a mocker or he will hate you; rebuke a wise man
and he will love you. Instruct a wise man and he will be wiser still; teach a righteous man and he will add to his learning.” (Prov. 9:7-9).