"Lechem chukeinu," our daily bread.
This phrase likewise occurs in Proverbs 30:8, where it is written, "Give me neither poverty nor riches, but provide me with my daily bread (lechem chuki)." The Hebrew here suggests food that is given by ordinance (chok), but the verb might also derive from a related Hebrew verb (chakok) meaning "to engrave." Since God has created us with an "engraved" hunger and thirst, we must ultimately look to Him for our sustenance and life.
"Kingdom bread" is the really the Bread of Life, which Jesus said truly satisfies our inner hunger. As we seek first His Kingdom ("Thy Kingdom come") and His Righteousness ("Thy will be done"), we are assured that the needs for this day of kingdom life will indeed be met (Matthew 6:33-34).