Rashi, on Isa 39:3

“Then Isaias the prophet came to king Ezechias, and said to him: What said these men, and from whence came they to thee? And Ezechias said: From a far country they came to me, from Babylon.”

““They have come to me from a distant country” This is one of three people whom the Holy One, blessed be He, tested and found to be a chamber pot: Cain, Hezekiah, and Balaam. Hezekiah should have replied, “You are a prophet of the Omnipresent. Yet you ask me?” Instead, he commenced to become haughty, and said, “They have come to me from a distant country.” Therefore, he was punished, and because he rejoiced over them and fed them on his table. Similarly, Balaam, to whom He said, “Who are these men with you?” (Num 22:9) And he replied and said, “Balak the son of Zippor sent them to me.” Similarly, Cain, to whom He said, “Where is your brother Abel?” (Gen. 4:9) He should have replied, “Lord of the Universe, are not all hidden things revealed to You?” As it is stated in Tanhuma.”

Imported from an open dataset — not yet checked against the printed edition.