"And you shall love the L-rd your G-d with all your heart, with all your
soul, and with all your might (me'od)" (Deuteronomy 6:4). "With all your
heart" -- with both your inclinations, with your good inclination and with your evil inclination. "With all your soul" -- even to the point that someone takes your life. "With all your meod" -- with all your money. Another interpretation: "With all your me'od" -- whatever measure (middah) He metes out (moded) to you, thank (modeh) Him exceedingly (me'od me'od).
Talmud, Berachot 54a