Mark 6:52

because they did not understand concerning the loaves, but their hearts were hardened.

Mark 3:5

And looking around at them with anger, grieved at the hardness of their hearts, he said to the man, "Stretch out your hand." And he stretched [it] out, and his hand was restored.

Mark 8:17-21

And knowing [this], he said to them, "Why are you discussing that you have no bread? Do you not yet perceive or understand? Have your hearts been hardened?

Isaiah 63:17

Why do you make us wander, Yahweh? You harden our heart from your ways {so that we do not fear} you. Turn back for the sake of your servants, the tribes of your inheritance.

Matthew 16:9-11

Do you not yet understand or do you not remember the five loaves for the five thousand, and how many baskets you took up?

Mark 7:18

And he said to them, "So are you also without understanding? Do you not understand that everything [that is] outside that goes into a person [is] not able to defile him?

Mark 16:14

And later, [while] they were reclining at table, he appeared to the eleven. And he reprimanded their unbelief and hardness of heart, because they did not believe those who had seen him [after he] had been raised.

Luke 24:25

And he said to them, "O foolish and slow in heart to believe in all that the prophets have spoken!

Romans 11:7

What then? What Israel was searching for, this it did not obtain. But the elect obtained [it], and the rest were hardened,

Treasury of Scripture Knowledge

Summary

For they considered not the miracle of the loaves: for their heart was hardened.

General references

Bible References

They

Mark 7:18
And he said to them, "So are you also without understanding? Do you not understand that everything [that is] outside that goes into a person [is] not able to defile him?
Mark 8:17
And knowing [this], he said to them, "Why are you discussing that you have no bread? Do you not yet perceive or understand? Have your hearts been hardened?
Matthew 16:9
Do you not yet understand or do you not remember the five loaves for the five thousand, and how many baskets you took up?
Luke 24:25
And he said to them, "O foolish and slow in heart to believe in all that the prophets have spoken!

Their

Mark 3:5
And looking around at them with anger, grieved at the hardness of their hearts, he said to the man, "Stretch out your hand." And he stretched [it] out, and his hand was restored.
Mark 16:14
And later, [while] they were reclining at table, he appeared to the eleven. And he reprimanded their unbelief and hardness of heart, because they did not believe those who had seen him [after he] had been raised.
Isaiah 63:17
Why do you make us wander, Yahweh? You harden our heart from your ways {so that we do not fear} you. Turn back for the sake of your servants, the tribes of your inheritance.

General references

Matthew 15:16
But he said, "Are you also still without understanding?