Historically it has been the consensus that sacred things and pearls refer to gospel truths (Matthew 13:44–46) and that this verse should be understood in the context of early church mission work (Matthew 10:14; Mark 6:11; Luke 9:5; Luke 10:11; Acts 13:51; Acts 18:6).1 As such, Jesus is warning his disciples not to share gospel truths with those who have no desire to hear and listen, those who are continually unappreciative (Matthew 15:14).2 In the context of judgment, he is encouraging disciples to show discernment. There is no point correcting those who will not receive correction (Proverbs 9:8; Proverbs 23:9).3 Refraining from critical judgment must not be understood as a licence to tolerate sin and evil.4
Despite the fact that the historical interpretation is common and widespread, it is very likely to be wrong since it relies on Matthew 13:44–46 to interpret Jesus’ reference to pearls and sacred things rather than the immediate context or the context of the Sermon on the Mount as a whole. If we allow these contexts to inform our interpretation, then pearls and sacred things can be understood instead as a reference to fellow believers.5 This makes more sense in the light of what Jesus has just said about judgment (Matthew 7:1–5). He is talking about the way in which Christians treat fellow believers, he is not talking about the gospel message itself. As such, Jesus is warning his disciples not to exercise a judgmental attitude toward their brother, thereby treating him as if he were not a brother at all and throwing him out to be at the mercy of the savage enemies of the kingdom.6
6 “Do not give dogs what is holy, and do not throw your pearls before pigs, lest they trample them underfoot and turn to attack you.