A.T. Robertson Commentary John 6:61

"But Jesus knowing in himself that his disciples murmured at this, said unto them, Doth this cause you to stumble?" — John 6:61 (ASV)

Knowing in himself (ειδως εν εαυτω). Second perfect active participle of οιδα. See 2:25 for this supernatural insight into men's minds.

Murmured (γογγυζουσιν). Present active indicative retained in indirect discourse. See 41 for γογγυζω.

At this (περ τουτου). "Concerning this word."

Cause to stumble (σκανδαλιζε). Common Synoptic verb from σκανδαλον for which see Mt 5:29. In John again only in 16:1.