What does Matthew 27:36 mean?

That the soldiers who nailed Jesus to the cross are assigned to "keep watch" is not an unusual part of the process. In fact, this is a necessary aspect of crucifixion. This method of execution was meant to stretch an agonizing death over a long period of time. Crucifixion nails were applied to deliberately avoid major blood vessels, so the victim would suffer filthy, bleeding wounds, but not a quick death. A person taken off the cross not long after being nailed could survive if they were able to fight off infection. Historical records report a rare fraction of victims surviving crucifixion in this way, as difficult as that is to imagine.

This meant that a crucified person, left unattended, could possibly be rescued by friends or family. Matthew adds this detail to counter those who might question the validity of Jesus' death or resurrection. The suggestion that He did not actually die, but was taken down and later appeared, cannot withstand reason. He was under watchful guard all the way through to His final breath. He was never alone or unattended while still alive. John, who was very close to the cross at the moment of Jesus' death (John 19:25–27), witnessed further details confirming this fact (John 19:31–37).