Reference for Bava Kamma 163:11
ת"ר חמשה דברים נאמרו בשום משביע ומשחין ומצהיל פנים ומרבה הזרע והורג כנים שבבני מעיים וי"א מכניס אהבה ומוציא את הקנאה:
as it says: <i>Ho, everyone that thirsteth come ye for water</i>.<span class="x" onmousemove="('comment',' Isa. LV, 1. ');"><sup>18</sup></span> It thus means that as they went three days without Torah they immediately became exhausted. The prophets among them thereupon rose and enacted that they should publicly read the law on Sabbath, make a break on Sunday, read again on Monday, make a break again on Tuesday and Wednesday, read again on Thursday and then make a break on Friday so that they should not be kept for three days without Torah.'<span class="x" onmousemove="('comment',' [Why then was it necessary for Ezra to enact this?] ');"><sup>19</sup></span>