Reference for Yevamot 209:16
אמר רב שמואל בר אוניא אמר רב מנין לגזר דין של צבור שאינו נחתם אינו נחתם והא כתיב (ירמיהו ב, כב) כי אם תכבסי בנתר ותרבי לך בורית נכתם עונך לפני
Rabbah and Abaye were both descendants of the house of Eli. Rabbah who engaged in the study of the Torah lived forty years. Abaye, however, who engaged in the study of the Torah and the practice of lovingkindness, lived sixty years. Our Rabbis taught: There was a certain family in Jerusalem whose members used to die when they were about the age of eighteen. When they came and acquainted R. Johanan b. Zakkai [with the fact,] he said to them: 'perchance you are descendants of the family of Eli concerning whom it is written in Scripture. And all the increase of thy house shall die young men;<span class="x" onmousemove="('comment',' I Sam. II, 33. ');"><sup>39</sup></span> go and engage in the study of the Torah, and you will live'. They went and engaged in the study of the Torah and lived [longer lives]. They were consequently called 'The family of Johanan', after him.