In his response to the Pharisees in today's reading, Jesus quotes the Shema, the great prayer from Deuteronomy 6:4, which begins, "Hear, O Israel, the Lord our God is one Lord" (RSV). However, Jesus subtly changes the wording. Instead of saying that we are to love the Lord with all our heart, soul, and might, Jesus says we must love with our heart, soul, and mind.
So what's the big deal? What's the difference between might and mind?