Matthew 5 and Matthew 28 are from entirely different contexts and cannot be simply combined

The two passages are from different moments in Jesus's ministry. Winger demonstrates the problem with mechanically combining them using a reductio ad absurdum: Matthew 10:5 has Jesus commanding his disciples not to go to Gentiles or Samaritans. If Matthew 28 means "teach all nations to do everything Jesus told the disciples," then we are forbidden from going to Gentiles—which directly contradicts Matthew 28 itself. The Matthew 10:5 command was temporary and context-specific, just as other Mosaic commands may be.