Don't work for the food which perishes, but for the food which remains to eternal life, which the Son of Man will give to you. For God the Father has sealed him."
Now many therefore of his disciples, when they heard this, said, [Man,] These are tough sayings; who can hear it? And when Jesus knew in himself that his disciples murmured at it, he said unto them, Does this offend you? What and if you will see the Son of man ascending up where he was before? ( John 6:60-62 )