This is a symbolic action to show that they reject the people of the city. Alternate translation: "Just as you rejected us, we thoroughly reject you. We even reject the dust from your town that clings to our feet" (See: [[rc://en/ta/man/jit/translate-symaction]])
Since Jesus was sending these people out in groups of two, it would be two people saying this. So languages that have a dual form of "we" would use it. (See: [[rc://en/ta/man/jit/figs-exclusive]])
The phrase "But know this" emphasizes the importance of what is said next. Alternate translation: "But be aware that the kingdom of God has come near" or "But be sure of this: The kingdom of God has come near"
The abstract noun "kingdom" can be expressed with the verbs "reign" or "rule." See how you translated a similar sentence in [Luke 10:8](../10/08.md). Alternate translation: "God will soon rule everywhere as king" or "The proof that God is reigning is all around you" (See: [[rc://en/ta/man/jit/figs-abstractnouns]])