play someone a turn

I have no idea. It's odd English.

Sorry, I just note this sentence without the whole paragraph and I forget the derivation... Thank you!

Without further context, I would interpret it as: He saw two farmers working in their fields and decided to play a trick on them.

Ah! Yes, you are right! But what's 'turn' mean here? A turn of game?

"To give a turn" is to give a surprise or shock. "Turn" can also mean an unexpected experience (a turn of events).

The verb "behold" is rarely used now. It indicates that the sentence is from some old fable.

To do someone a good (or bad) turn is to do something helpful (or unhelpful) for them. To play someone is make a fool of them, to trick or mislead them. The writing style here is very old fashioned. I would guess that the phrase would have been more familiar to readers at the time it was written than it is today.

It springs from the book named THE HERO WITH A THOUSAND FACES. Indeed, it talks about a legend spreading among some tribes in this contexts. Thank you!

Yep! This book was written 65 years ago! Thank you!

The language would have been very dated 65 years ago, The writer is reporting an old legend,

Yep, but his discourse still sparkles of wit.