Reference for Eruvin 125:20
אמר ר' חייא בר אבא אמר רבי יוחנן כל המורה הלכה בפני רבו ראוי להכישו נחש שנאמר (איוב לב, ו) ויען אליהוא בן ברכאל הבוזי ויאמר צעיר אני לימים וגו' על כן זחלתי וכתיב (דברים לב, כד) עם חמת זוחלי עפר
- And according to your conception what need was there for the mention of his name and the name of his father? But the fact is that all the details were given in order that it be not said that the whole story was a fable. R'Hiyya B'Abba stated in the name of R'Johanan: Whoever gives a legal decision in the presence of his Master deserves to be bitten by a snake, for it is said: And Elihu the son of Barachel the Buzite answered and said: I am young, etc. wherefore I held back,<span class="x" onmousemove="('comment',' rt. Job. XXXII, 6.');"><sup>35</sup></span>