Jesus enjoined them, “Watch out, guard against the leaven of the Pharisees and the leaven of Herod.” They concluded among themselves that it was because they had no bread.
Gospel's Commentary
Today some disciples get into the boat with Jesus. However, they forgot to take some bread for the sailing. When Jesus warns them against the “leaven” (the dangers) of the Pharisees, they think the Lord is scolding them for their short memory and their forgetting the provisions for the voyage.
The Lord is inviting us to be less worried about the bread (the telephone, our shoes…) and attend more to “the bread of Truth”, without letting ourselves be fooled by the shiny little crystals of life that invade our heart.