The Spartans were very grateful for all he had done for them, so they gladly took this oath, and Lycurgus left the place. Some time after, he came back to Greece; but, hearing that the Spartans were thriving under the rules he had laid down, he made up his mind never to visit Sparta again.
It was thus that the Spartans found themselves bound by solemn oath to obey Lycurgus’ laws forever; and as long as they remembered this promise, they were a thriving and happy people.
From: H. A. Guerber, The Story of the Greeks; edited for this online publication, by ELLOPOS BLOG
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