Reference for Yoma 150:11
תנו רבנן (תהלים עח, כה) לחם אבירים אכל איש לחם שמלאכי השרת אוכלין אותו דברי ר"ע וכשנאמרו דברים לפני רבי ישמעאל אמר להם צאו ואמרו לו לעקיבא עקיבא טעית וכי מלאכי השרת אוכלין לחם והלא כבר נאמר (דברים ט, ט) לחם לא אכלתי ומים לא שתיתי אלא מה אני מקיים אבירים לחם שנבלע במאתים וארבעים ושמונה אברים
He went up to the roof and heard a child which read: When I heard, my inward parts trembled.<span class="x" onmousemove="('comment',' Hab. III, 16.');"><sup>19</sup></span> Thereupon he said: One knows from this that R'Hisda is dead.<span class="x" onmousemove="('comment',' This story is very satisfactorily explained in Schatzkes' Mafteah I, Warsaw, 1866. R. Hisda, in spite of his great riches, was very frugal in his habits and so economical that he would not entrust even the management of wood to any servant, but himself every day handed wood to the cooks (Git. 56a) . Although he would find the quails among his twigs, he would prevent anyone from laying his hands upon these delicacies. His son-in-law Raba, therefore, arranged with a tenant-farmer to bring them. His failure to bring them one day Raba rightly attributed to the thought that something had happened which rendered such service unnecessary. To this inference he added, according to widespread custom, the additional reliance on the implications of a text the first child he met would be studying. When that text suggested evil news the 'evidence was complete'.');"><sup>20</sup></span> It is for this reason that people say: By th merit of his master eats the pupil.