JOHN 6:59-62 NKJV

These things He said in the synagogue as He taught in Capernaum.

Therefore many of His disciples, when they heard this, said, “This is a hard saying; who can understand it?”

When Jesus knew in Himself that His disciples complained about this, He said to them, “Does this offend you? What then if you should see the Son of Man ascend where He was before?

JOHN 6:59-62 NKJV

John 6:59 the synagogue … in Capernaum: In the ruins of a synagogue at Capernaum, a large stone with a pot of manna engraved on it has been found. Some have suggested that perhaps the synagogue in this passage had such a symbol.

John 6:60 Disciple means “learner” and is used in a variety of ways in the NT. It can include unbelievers (v. 64), believers who go beyond initial faith to baptism and obedience (8:31), or it can mean the apostles in particular (2:11). The context determines what meaning is intended. Here it simply means learner. Some of the crowd were students; they came to learn. Not all of these had believed in Christ. It was hard for the Jewish learners to accept the idea of eating flesh and drinking blood. Jews were forbidden to even taste blood.

John 

6:61, 62 Jesus was asking, “If the thought of eating flesh and drinking blood offends you, would you be further offended at the idea of My ascension?”