What is significant about shaking dust from your feet?

To shake the dust from you feet simple means don't take any part of some ones spirit with you...... after you give the truth and if not accepted keep moving and let GOD handle it,don't spend time trying to force someone to listen!!!

When Jesus came proclaiming the Kingdom He didn’t say, “Repent because you have been sinning.” Sin is not the issue in the Kingdom. The issue is allegiance. Repentance means to repudiate something you have believed in and clung to in order to believe in and cling to something else. Repentance is the call to change our minds about the rule of our lives. Repentance is the call for us to change kingdoms. The Kingdom of God is spiritual, it doesn’t work in the carnal mind. So whether a man is sinning or being religious he must repent, because the Kingdom only works in the spiritual mind. Kingdoms clash. Every kingdom wants to rule. When one kingdom is in power and another kingdom comes to take the dominion there is warfare. The message of the Christ is repentance unto another Kingdom. Another rule comes into our lives which will cast out the demons and establish the mind of Christ. God has called upon us to repent of the rule of the flesh, the rule of the carnal mind, the rule of the world, the rule of religion, the rule of the church-systems, the rule of laws and external ordinances, and all that pertains to the old order. Repent of sin? Yes! But much more. It is a whole economy, a whole mentality, a whole way of life, an entire system of things that we must repent of in order to enter into the Kingdom Rule of God. When we talk about entering the Kingdom we are changing many things; there must be a change in our whole world of existence, where we think we came from, who we think we are, what we think we are, what our purpose is in this world, how we live in this world, and where we think we are going. All our concepts and realities change. In our natural birth we came from the earth. In our spiritual birth we came from heaven. We are shedding that Adam identity, that Adam delusion, the Adam mind, the Adam life-style, the Adamic wisdom, knowledge and ability.

There is an interesting and illustrative incident in the ministry of Jesus that speaks powerfully to us of the new mind of the Kingdom. “After these things the Lord appointed other seventy also, and sent them two and two before His face into every city and place, whither He Himself would come. Therefore He said unto them, Into whatsoever city ye enter, and they receive you, eat such things as are set before you: and heal the sick that are therein, and say unto them, The kingdom of God is come nigh unto you. But into whatsoever city ye enter, and they receive you not, go your ways out into the streets of the same, and say, Even the very dust of your city, which cleaveth on us, we do WIPE OFF against you: notwithstanding be ye sure of this, that the kingdom of God is come nigh unto you” (Lk. 10:1-2,8-11). Jesus sent the disciples out to heal the sick. The healings were a sign and a sign is a message. The message was that the Kingdom of God had come. The healings were done by the power of the Kingdom. They were the sign, the declaration of the Kingdom, the proof that the power of another Kingdom was already at work in their midst. Jesus said to the scribes and Pharisees, “O, ye hypocrites, ye can discern the face of the sky; but ye cannot discern the signs of the times.” In other words, “You don’t understand the message that sounds forth when I do these things.”

Matthew records Jesus’ instructions to the seventy in these words, “And whosoever shall not receive you, nor hear your words, when ye depart out of that house or city, shake off the dust of your feet.” One thing is certain — the disciples were not just shaking dust off their clothes and shoes. They were saying something. By that action they were sending a message. The message was just this. When the people rejected the ministry of the disciples they were rejecting the Kingdom of God, because that is what they were preaching, demonstrating and manifesting. Jesus instructed them, “When the people reject the Kingdom of God shake that dust off of you, shake that Adamic nature off of you, don’t let that earth-bound mentality cling to you, or find a place in you, don’t be influenced or affected by their words or actions, don’t walk away from the city with the same kind of serpent meat they are providing!”

This brings us back to the curse laid upon the serpent in the beginning. The ancient serpent, having beguiled Eve, became the recipient of the first curse in history. “And the Lord God said unto the serpent, Because thou hast done this, thou art cursed above all cattle, and above every beast of the field; upon thy belly shalt thou go, and dust shalt thou eat all the days of thy life” (Gen. 3:14). This is a symbol and the Deceiver, Satan, that old Serpent, the Devil, has to eat dust! The metaphor can be more clearly understand when we hear the judgment handed out to the man. God said, “In the sweat of thy face shalt thou eat bread, till thou return unto the ground; for out of it wast thou taken: for DUST THOU ART, and UNTO DUST shalt thou return” (Gen. 3:19). So that first Adam, the fleshly man, that cursed man, is declared by the counsel of the Lord God to be dust. Said the wise man, “He knoweth our frame; He remembereth that we are dust” (Ps. 103:14). That we are DUST! Not very flattering, not very complimentary, is it? This great gob of mud called man, strutting his superior know-it-all attitude even in the face of the Almighty! Dust! Our FRAME! Adam’s name could just as well have been called “Dusty.” The mind of Adam is the earthly mind, and it always minds earthly things. It is a dust-mind.

The message is clear — Adam and those belonging to him are of the earth, earthy. The Holy Spirit bears witness, “And so it is written, The first man Adam was made a living soul; the last Adam was made a quickening spirit. The first man is of the earth, earthy: the second man is the Lord from heaven. As is the earthy, such are they also that are earthy: and as is the heavenly, such are they also that are heavenly. And as we have borne the image of the earthy, we shall also bear the image of the heavenly” (I Cor. 15:45-49). The Amplified Bible reads, “The first man was from out of the earth, made of dust — earth minded; the second man is the Lord out of heaven. Now those who are made of the dust are like him who was first made of the dust — earth minded. And just as we have borne the image of the man of dust, so shall we and so let us bear also the image of the Man of heaven.”

In short, shaking the dust of your feet is way of indicating uncleanliness.

From the Believers Bible Commentary:

R. Guelich suggests that shaking off dust from the feet, the symbolic act that Jesus’ disciples were to carry out when leaving a rejecting village (6:11), has a threefold meaning (322–3):

• It announces the inevitability of judgment (since further contact and opportunity for repentance is symbolically cut off).

• It declares that the missionaries have done their job and are washing their hands of further responsibility (Ezek. 3:21; 33:1–9).

• It labels that village as pagan.

Of these three, the third is the most provocative. Jews would shake off “pagan” dust before entering the “holy land” (Str.-B, 1:115). Likewise, Jesus’ emissaries demonstrate that villages rejecting them and the one who sent them have lost their inheritance in the people of God.

A similar message is conveyed via John’s symbolic act of baptizing Jews (1:5), an act normally reserved for converts to Judaism. John is thereby symbolically reinstating Jews into the people of God, implying that without his baptism, they are outsiders to Israel. The present text about shaking off “pagan dust,” however, takes this a step further. People are invited to reinstate their membership in the people of God; those who reject God’s messengers are symbolically excluded.

Other NT references to shaking off dust include all three of the meanings suggested above, though sometimes one of them is more prominent than the others (Matt. 10:14; Luke 9:5; 10:11; Acts 13:51; 18:6). Acts 18:6 in particular seems to highlight all three aspects. As he leaves the Corinthian synagogue, Paul shakes the dust off his clothing and says, “Your blood be on your own heads [meaning 1]. I am clear of my responsibility [meaning 2]. From now on I will go to the Gentiles [meaning 3]” (NIV). With his final line, Paul reverses the usual Jewish practice of cleansing their feet before moving from Gentile to Jewish territory. Paul is moving from Jewish territory (the synagogue) to Gentile territory (the house of Titius Justus) and shaking off the dust before doing so. Believing Jews join him as he moves toward a more fruitful mission field.

And from "The New Manners and Customs of the Bible:"

For Jews to shake dust off their feet was a sign that Gentile territory was unclean. In the New Testament this action indicates that those who have rejected the gospel have made themselves as Gentiles and must face the judgment of God. (See also Acts 13:51) To sprinkle dust on the head was a sign of mourning (Joshua 7:6), and to sit in dust denotes extreme affliction (Isaiah 47:1). “Dust” is used to denote the grave (Job 7:21). To lick the dust is a sign of abject submission (Psalms 72:9); and to throw dust at someone is a sign of abhorrence (2 Samuel 16:13; Acts 22:23). To bite the dust is to suffer a defeat. It became a common expression through its use in American movies about the early west.

In particular, I find the linkage between "shaking the dust off your feet" and "biting the dust" to be interesting.