Matt 7:6

7:6 what is holy. A reference to the evidences of the kingdom, such as the healings and the exorcisms, which may explain why Jesus did no miracles for unbelievers. But “what is holy” would also include the preaching of the kingdom; believers should not continue to preach to people who have rejected the gospel with contempt and scorn (10:14; 15:14). The Book of Acts illustrates the principle in practice (Acts 13:44–51; 18:5, 6; 28:17–28).