Dogs and hogs are both intelligent animals.  Both frequently appear on lists of the most intelligent animals. 

However, there are things that are not appreciated or valued by these animals.  Consider how Jesus used this in his teaching. 

“Do not give what is holy to the dogs; nor cast your pearls before swine, lest they trample them under their feet, and tear you in pieces” (Matthew 7:6). 

The holy is not to be presented to dogs.  To what does “holy” refer?  (1) This seems to refer to that which has been sacrificed to God.  In some sacrifices, the priests and holy worshippers were permitted to eat part of the meat (e.g. Leviticus 6:24-30; 7:15-21).  What was not ate was to be burned (Leviticus 7:17).  It was not to be fed to the dogs.  They would not appreciate the meaning and significance of the sacrifice (2) William Barclay suggested that an earring could be intended.  He explained that the Hebrew word for holy (kadash or qadosh) and the Aramaic word for earring (kadasha or qadasha) contain the same consonants and that Hebrew was then written without vowels (William Barclay, The Gospel of Matthew, studylight.org).  It is an interesting theory.  However, the current textual evidence that we have is from Greek manuscripts, not Hebrew. No standard English translation renders it “earring” (The Passion Translation does).

Pearls are not for swine.  They will not appreciate the value of the pearls (cf. Matthew 13:45-46).  They want food, not pearls.  Consider these words by J.W. McGarvey, “If a herd of hungry and ferocious hogs are called to be fed, and instead of grain you throw them a basket of pearls, they will not only trample the pearls under their feet, but in their eagerness for the expected food they may rush upon you, pull you down, and tear you to pieces” (J.W. McGarvey, On Matthew and Mark, p. 70).  We should keep in mind that the swine are probably feral or undomesticated.  Swine was unclean to Israelites (Leviticus 11:7-8; Deuteronomy 14:8). 

What is the message?  This is not about literal dogs and hogs.  (1) This concerns correction (notice context Matthew 7:1-6).  Jesus is teaching that not all will properly receive correction (cf. Proverbs 9:7-8; 15:12; 23:9).  J.W. McGarvey commented, “Some men, when you press the claims of truth on their attention, will not only despise the truth, but persecute you for annoying them with it.  When such men are known they are to be avoided” (ibid).  (2) There is an application to preaching.  The kingdom of heaven is compared to a pearl of great price (Matthew 13:45-46).  However, not all will appreciate its value.  Consider these words, “In the teaching of the truth we must spend some time in judging or discerning the receptiveness of the people we are seeking to reach.  This can be readily seen by the way they treat the word.  If they have no more regard for truth than a ‘dog’ has for holiness or a ‘hog’ has for pearls, then we should move on to more fruitful fields of endeavor.  The Bible is too sacred a volume to allow godless souls to trample it underfoot and even persecute us for presenting the ‘Good News’” (Kerry Knight in the book The Sermon on the Mount, 7^th Annual Spiritual Sword Lectureship, p. 231).  Time is short.  Those needing salvation are many.  If someone makes clear that he does not appreciate the message, then move on to another who does appreciate it.  Let us not waste precious time and energy on those without interest.     

Fun Fact:  Have you heard of Hogzilla?  It was shot in Alapaha, Georgia in 2004 by Chris Griffin on Ken Holyoak’s hunting preserve.  It was reported to have been 12 feet long and weighted 1,000 pounds.  National Geographic exhumed the body.  They concluded that it was between 7 ½ and 8 feet long and weighed 800 pounds.  It was a hybrid of wild and domesticated swine (The Mystery of Hogzilla Solved, abcnews.go.com; Legend of Hogzilla Proven True, espn.com).