Temurah 16a, cited briefly in Rashi: When a Rebbi (who has not yet learned everything) agrees to a Talmid's request to teach him, Hashem enlightens both of them. If the Rebbi refuses, "Ashir va'Rash Nifgashu Oseh Chulam Hashem" (22:2). Hashem had made the Rebbi wise, but now He makes him foolish, and vice-versa for the Talmid.

Malbim citing Shocher Tov 7: Poverty came to enter the ark; No'ach did not let it, for it has no mate. It encountered Sheker going to the ark. They married, so each would have a mate. They stipulated that whatever Sheker gives birth to, it will bear deficiency; what Sheker will profit, poverty will take. "Rash" is poverty. Ish Techachim (guile) is Sheker. This teaches that poverty and Sheker, each by itself is not proper to last; together, they last. Guile lasts, in order that what one profits from it, poverty will take it. People should take Musar from this, that Sheker and guile will not succeed. They met, and via this Hashem enlightens both of their eyes, so people will open their eyes and not swindle any more, and poverty will cease. This is the purpose of their meeting and marriage!