To the cryptic practice of the red heifer, the Rabbis applied a verse in Kohelet (7:23): I said, Let me grow wise, but wisdom was far away from me. What did they mean? When some part of God's law does not make sense to us, we can either decide the problem is with the Torah or we can be humble and consider if the problem is with us. The Rabbis wanted us to take the second approach and so they quoted this verse that encourages a humble attitude: I said, Let me grow wise, but even so, wisdom was far away from me.