Is it relevant that the man on the opposite side is a priest?
Is it relevant that they are riding in a small coach or could it be a small car with facing seats?

>A woman with her husband seats on opposite side of a bench (? / seat) to a catholic priest in a small coach (wagon) travelling on a country (read - bad) road. On one of the bump of the road the wagon is shaken and a man hits the priest by his head into his belly. After that incident the priest turns to a woman and says "Thank you". Why did he say it?
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>Think outside of the box < g >