Humility; Har Sinai and Moshe Rabbeinu (Avos 2:6)
Avot2: 6
אַף הוּא רָאָה גֻלְגֹּלֶת אַחַת שֶׁצָּפָה עַל פְּנֵי הַמָּיִם. אָמַר [לָהּ]: ”עַל דַּאֲטֵפְתְּ — אַטְּפוּךְ, וְסוֹף מְטַיְּפַיִךְ — יְטוּפוּן”.
He also saw a skull floating on the water. He said to it: “Because you caused [the heads of] others to float, [others] caused [your head] to float; and eventually those who caused you to float will be caused to float themselves.”