“Who are the dogs and swine in Matthew 7:6?”
“Give not that which is holy unto the dogs, neither cast ye your pearls before swine, lest they trample them under their feet, and turn again and rend you.”
A “pearl” is a living stone, a precious stone created by a living creature. Since Peter says that to come to the Lord under the kingdom program was to come to Him “as unto a living stone” (1 Pet. 2:4), the “pearl of great price” was Christ (Matt. 13:46), the most “precious” stone of all (1 Pet. 2:6,7). Hebrews who found Christ under the kingdom program “sold all” to obtain Him (Matt. 13:46 cf. Luke 18:22; Acts 2:45). When they associated themselves with the Lord in this way, they themselves became “lively stones” (1 Pet. 2:5), and these are the pearls the Lord was saying should not be cast to the swine. So who are the swine?
Swine were associated with demons (Mark 5:11-13), and the only time swine and dogs are mentioned together (2 Pet. 2:22), they are associated with “false prophets” (v. 1) who, like Balaam, knew the way of God but had “forsaken the right way” (vv. 15,16), men who had “known the way of righteousness” (v. 21) but chose to “turn from the holy commandment delivered unto them” (v. 21), showing they were Hebrews who were never saved (1 John 2:19). In the Tribulation that the Lord was preparing His Hebrew hearers to go through, there will be a strong temptation to cast the lively stone pearls of believers into the clutches of these demonically-controlled false prophets. This temptation will be so strong that even family members might sell one another out (Micah 7:5,6) thinking they are serving God (John 16:2). If family members yield to this temptation, however, the Lord warns that the swine of these demonically-controlled false prophets will “turn again and rend” them. source