Luke 10:31

And by chance - Κατα συγκυριαν properly means the coincidence of time and circumstance. At the time in which the poor Jew was half dead, through the wounds which he had received, a priest came where he was. So the priest's coming while the man was in that state is the coincidence marked out by the original words.

Priest and Levite are mentioned here, partly because they were the most frequent travelers on this road, and partly to show that these were the persons who, from the nature of their office, were most obliged to perform works of mercy; and from whom a person in distress had a right to expect immediate succor and comfort; and their inhuman conduct here was a flat breach of the law, Deuteronomy 22:1-4.

By chance - Accidentally, or as it happened. It means that he did not do it with a "design" to aid the man that was wounded.

A certain priest - It is said that not less than 12,000 priests and Levites dwelt at Jericho; and as their business was at Jerusalem, of course there would be many of them constantly traveling on that road.

When he saw him - He saw him lie, but came not near him.

Passed by on the other side - On the farther side of the way. Did not turn out of his course even to come and see him.

10:31 The common translation is, by chance - Which is full of gross improprieties. For if we speak strictly, there is no such thing in the universe as either chance or fortune. A certain priest came down that way, and passed by on the other side - And both he and the Levite no doubt could find an excuse for passing over on the other side, and might perhaps gravely thank God for their own deliverance, while they left their brother bleeding to death. Is it not an emblem of many living characters, perhaps of some who bear the sacred office? O house of Levi and of Aaron, is not the day coming, when the virtues of heathens and Samaritans will rise up in judgment against you?