民数記 16:4

ויפל על פניו [AND WHEN MOSES HEARD IT,] HE FELL UPON HIS FACE because of the rebellion, for this was already the fourth offence on their part: when they sinned by worshipping the Golden Calf, it states, (Exodus 32:11) "And Moses besought [the Lord]”; in the case of the “people who complained”, (Numbers 11:1) it states: “and Moses prayed”; at the incident of the “spies”, (Numbers 14:13) “And Moses said unto the Lord, ‘When the Egyptians shall hear it ... [and now I beseech Thee etc.]”; but now at the rebellion of Korah, his hands sank down (he felt himself powerless) A parable! This may be compared to the case of a prince who sinned against his father and for whom his (the father’s) friend gained forgiveness once, twice, three times. When he offended for the fourth time the friend felt himself powerless, for he said, “ How long can I trouble the king? Perhaps he will not again accept advocacy from me!” (Midrash Tanchuma, Korach 4).

וַיִּשְׁמַ֣ע מֹשֶׁ֔ה וַיִּפֹּ֖ל עַל־פָּנָֽיו׃

And when Moshe heard it, he fell on his face: