{Upon this} (ek toutou). Same idiom in  19:12 . "Out of
this saying or circumstance." Jesus drew the line of cleavage
between the true and the false believers. {Went back} (ap(886c)thon
eis ta opis(935c)). Aorist (ingressive) active indicative of
aperchomai with eis ta opis(935c), "to the rear" (the behind
things) as in  18:6 . {Walked no more with him} (ouketi met'
autou periepatoun). Imperfect active of peripate(935c). The crisis
had come. These half-hearted seekers after the loaves and fishes
and political power turned abruptly from Jesus, walked out of the
synagogue with a deal of bluster and were walking with Jesus no
more. Jesus had completely disillusioned these hungry
camp-followers who did not care for spiritual manna that
consisted in intimate appropriation of the life of Jesus as God's
Son.