One of Israel’s most popular singers, Omer Adam, has rejected an offer to perform at the international singing competition Eurovision because rehearsals for the finale will be held on Shabbat.

According to a statement, he declined “despite the great honor,” and “thanks them from his heart for approaching him.”

Adam, while not Orthodox, has made it a matter of principle not to perform on Shabbat.

The finale of Eurovision is scheduled to take place in Tel Aviv on Saturday, May 18, with rehearsals taking place throughout the day.

Adam was born in the United States, grew up in Israel, and has risen to the top of the charts. His most popular song of 2018, “Sheni Meshugaim” (“Two Crazy People”) garnered more than 48 million hits last year on YouTube.