Luke 10:31

“And by chance a certain priest was going down that way, and when he saw him, he passed by on the other side.”

As we see above this verse is central to the chiasmus indicating its central importance. It is thus to be seen as of prime significance in the passage. In the first place it was an example of total lack of compassion and of pure self-interest. The priest saw the half-dead man lying there (note the deliberate connection with the idea of death) and passed by on the other side. And this a priest who served in the house of the Lord, who taught the Law, and who was called on by the Law to love his neighbour as himself including ‘strangers'. But Jesus probably intended us to see more than that. And that is that one reason that the priest passed by on the other side was because he was going up to the Temple to worship, and he thus did not want to be rendered unclean by tending one who was on the way to becoming a dead carcase. He saw his religious purity as more important to him than the man's need and persuaded himself that he was justified in leaving the man lying there because of the importance of his ritual duties. For it was clear to him that if the man was not already dead, he soon would be. And if he were to touch him he would then be unable to minister in the Temple. This is why he passed by ‘on the other side'. Ritual was to him more important than compassion and a human life.

And again there is in this the lesson that the whole priesthood of Israel had failed Israel, and that that was why Israel was like the victim of robbers. Their concentration on ritual had overridden their ideas of compassion and mercy. Indeed they themselves had become servants in a den of robbers. When it came to the need of Israel, they thus passed by ‘on the other side'.

‘By chance.' The expression shows that Jesus had no problem with speaking of ‘chance', that is of random uncontrolled happenings.