A blessing often heard on the state of Israel’s celebration of its 60 years of independence was, “Kein yirbu”, “so should they multiply”. This expression harks back to the beginning of Exodus.
Pharaoh, possessed by a paranoid sense that if the Israelites multiplied, they would join an invading force to bring about Egypt’s downfall, decides to abuse the Israelites in hope that that would cause their numbers to decline. “But the more they were oppressed, the more they increased and spread out — kein yirbeh v’chein yifrotz.” (Exodus 1:12). There is a proportional relationship between the degree of oppression and the number of children born to the Israelites.
Shorn of its association with enslavement, kein yirbu is a blessing for continued success. It offers congratulations for one’s current achievements and hope for future accomplishments in the same vein.
Kein yirbu is most commonly used when discussing children. One might say, “The Cohen family has just had another baby. Kein yirbu!”
Last Friday on an ask-the-rabbi phone-in, I heard a taxi driver ask whether he ought to reduce a customer’s fare in a case where he unwittingly took a route that turned out to be longer than an alternative. The rabbi’s answer: “Kein yirbu Yehudim kamocha b’Yisrael,” “May there be more Jews like you in Israel!”