Charles Ellicott Commentary John 6:60

"Many therefore of his disciples, when the heard [this], said, This is a hard saying; who can hear it?" — John 6:60 (ASV)

Many therefore of his disciples—that is, of the disciples in the wider sense; those who more or less fully were accepting His teaching, and were regarded as His followers. From John 6:64, the Apostles would seem to be included in the more general designation. In John 6:67 they are separately addressed.

This is an hard saying; who can hear it?—that is, not hard to be understood, but hard to hear, a stumbling block in the way of their faith. For the word itself, compare to Matthew 25:24. His meaning was, indeed, not understood by them, but the literal meaning was painfully clear, and one to which they will not listen. (Compare to John 10:20.) They do not raise any formal objection to Him, but friends and companions who had talked together about the Teacher and His teaching before, talk again now, and many of them who have followed Him up to this point can follow Him no more.