Contradiction with Matthew 10:14
In a similar situation, Jesus instructs the disciples to "shake off the dust of your feet" as a testimony against the town, aligning rather than contradicting.
Matthew 10:14: 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.
Contradiction with Luke 10:10-11
These verses echo the instruction in Luke 9:5 rather than directly contradicting, though they add the detail of stating, "The kingdom of God is come nigh unto you" as a part of the testimony.
Luke 10:10-11: But into whatsoever city ye enter, and they receive you not, go your ways out into the streets of the same, and say,
Contradiction with Acts 13:51
Here, Paul and Barnabas shake the dust off their feet against a city in a consistent manner with Luke 9:5, reflecting rather than opposing the teaching.
Acts 13:51: But they shook off the dust of their feet against them, and came unto Iconium.