Mark 8:14-21 NIV                            
 14 The disciples had forgotten to bring bread, except for one loaf they had with them in the boat. 15 “Be careful,” Jesus warned them. “Watch out for the yeast of the Pharisees and that of Herod.”
16 They discussed this with one another and said, “It is because we have no bread.”

17 Aware of their discussion, Jesus asked them: “Why are you talking about having no bread? Do you still not see or understand? Are your hearts hardened? 18 Do you have eyes but fail to see, and ears but fail to hear? And don’t you remember? 19 When I broke the five loaves for the five thousand, how many basketfuls of pieces did you pick up?” “Twelve,” they replied.
20 “And when I broke the seven loaves for the four thousand, how many basketfuls of pieces did you pick up?” They answered, “Seven.”

21 He said to them, “Do you still not understand?”