וְכָל־מְלָאכָה֙ לֹ֣א תַעֲשׂ֔וּ בְּעֶ֖צֶם הַיּ֣וֹם הַזֶּ֑ה כִּ֣י י֤וֹם כִּפֻּרִים֙ ה֔וּא לְכַפֵּ֣ר עֲלֵיכֶ֔ם לִפְנֵ֖י יְהוָ֥ה אֱלֹהֵיכֶֽם׃
And ye shall do no manner of work in that same day; for it is a day of atonement, to make atonement for you before the LORD your God.
Find Talmudic references to Leviticus 23:28: , passages from the Talmud Bavli and Yerushalmi.