Reference for Rosh Hashanah 41:8

שלח ליה רב הונא בר אבין לרבא כד חזית דמשכה תקופת טבת עד שיתסר בניסן עברה לההיא שתא ולא תחוש לה דכתיב (דברים טז, א) שמור את חדש האביב שמור אביב של תקופה שיהא בחדש ניסן

a leap year and have no scruples,<span class="x" onmousemove="('comment',' Although this follows the view only of an individual authority, as recorded in Sanh. 13b.');">¹⁷</span> since it is written, Observe the month [hodesh] of Abib,<span class="x" onmousemove="('comment',' Deut. XVI, 1.');">¹⁸</span> which signifies, See to it that the Abib of the cycle<span class="x" onmousemove="('comment',' I.e., the beginning of the vernal equinox. The day on which the vernal equinox begins is called Abib because on that day the corn begins to ripen by the effects of the sun (Rashi) . V. Sanh., Sonc. ed., p. 60 notes.');">¹⁹</span>

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