וַיִּגְּשׁ֣וּ עֲבָדָיו֮ וַיְדַבְּר֣וּ אֵלָיו֒ וַיֹּאמְר֗וּ אָבִי֙ דָּבָ֣ר גָּד֗וֹל הַנָּבִ֛יא דִּבֶּ֥ר אֵלֶ֖יךָ הֲל֣וֹא תַעֲשֶׂ֑ה וְאַ֛ף כִּֽי־אָמַ֥ר אֵלֶ֖יךָ רְחַ֥ץ וּטְהָֽר׃
And his servants came near, and spoke unto him, and said: ‘My father, if the prophet had bid thee do some great thing, wouldest thou not have done it? how much rather then, when he saith to thee: Wash, and be clean?’
Rashi
My Father! May [Job] be tried You are my Father. The Holy One, blessed be He, is the Father of all. If only Job were tried to eternity, in order that there be repentance among men of iniquity. And also to men Scripture speaks in this manner (II Kings 5:13): “‘Master (אבי), if the prophet spoke to you to do a difficult thing etc.’” Another explanation: אבי is like (Ecc. 12:5), “and the sexual desire (האביונה) will fail,” an expression of desire. Menachem (Machbereth p. 11) associated it in this manner, and this is its interpretation: אָבִי יִבָּחֵן אִיוֹב עַד נֶצַח, my wish and my desire are that Job should be tried to eternity (omitted in some editions).