Reference for Gittin 153:9

<br><br><big><strong>הדרן עלך מי שאחזו:</strong></big><br><br>

what [do we do]? — When R. Zera was once sitting before R. Assi, or, as others report, when R. Assi was sitting before R. Johanan, he said: The first day of the week and the second and third are called 'after the Sabbath'; the fourth and fifth days and the eve of Sabbath are called 'before the Sabbath.'

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