In Luke 9 Jesus sent out his twelve disciples to preach the kingdom of God, and to heal the sick. In verse 5, he told them “And whosoever will not receive you, when you go out of that city, shake off the very dust from your feet for a testimony against them.”
To shake off the dust meant to shake off all animosity, bitterness, resentment, and all other negative feelings and attitudes. Instead of carrying it with them, they were to shake it off and move on. Sometimes we may have bad memories that replay in our minds. Instead of dwelling on those things and being upset about them, we should shake off the dust and move on.
Philippians 3:13-15
Brothers, I do not consider myself to have won, but this one thing I do: Forgetting the things that are behind and stretching forward toward the things that are ahead, I press on in pursuit toward the goal for the prize of the upward calling of God in Christ Jesus. Let us, therefore, as many as are mature, think in this manner, and if you do think in any other manner, God will also reveal this to you.
We should forget the things that are behind and stretch forward toward the things that are ahead, focusing on the glorious future that is ahead of us after our Lord Jesus Christ returns, working hard now in doing things that will matter after he returns and that will produce eternal rewards.