Mark 6:52

52for they had not understood about the loaves; their hearts were hardened.

52for they had not gained any insight from the incident of the loaves, but their hearts were hardened.

52for they had not gained any insight from the incident of the loaves, but their heart was hardened.

52because they had not understood [the miracle of] the loaves [how it revealed the power and deity of Jesus]; but [in fact] their heart was hardened [being oblivious and indifferent to His amazing works].

52for they had not understood about the loaves, but their hearts had been hardened.

52They had not understood about the loaves. They were stubborn.