A.T. Robertson Commentary John 10:33

"The Jews answered him, For a good work we stone thee not, but for blasphemy; and because that thou, being a man, makest thyself God." — John 10:33 (ASV)

For a good work we stone thee not (περ καλου εργου ου λιθαζομεν). "Concerning a good deed we are not stoning thee." Flat denial that the healing of the blind man on the Sabbath had led them to this attempt (8:59) in spite of the facts.

But for blasphemy (αλλα περ βλασφημιας). See Ac 26:7 where περ with the genitive is also used with εγκαλουμα for the charge against Paul. This is the only example in John of the word βλασφημια (cf. Matthew 12:31).

And because that thou, being a man, makest thyself God (κα οτ συ ανθρωπος ων ποιεις σεαυτον θεον). In 5:18 they stated the charge more accurately: "He called God his own Father, making himself equal with God." That is, he made himself the Son of God. This he did beyond a doubt. But was it blasphemy? Only if he was not the Son of God. The penalty for blasphemy was death by stoning (Leviticus 24:16; 1 Kings 21:10,13).