John 6:63

If then you shall see, &c. Christ, by mentioning his ascension, by this instance of his power and divinity, would confirm the truth of what he had before asserted; at the same time, correct their gross apprehension of eating his flesh and drinking his blood, in a vulgar and carnal manner, by letting them know he should take his whole body living with him to heaven; and consequently not suffer it to be, as they supposed, divided, mangled, and consumed upon earth. (Challoner) --- The sense of these words, according to the common exposition, is this: you murmur at my words, as hard and harsh, and you refuse now to believe them: when I shall ascend into heaven, from whence I came into the world, and when my ascension, and the doctrine that I have taught you, shall be confirmed by a multitude of miracles, then shall you and many others believe. (Witham)