John 6:64

6:64 But there are some of you who do not believe.” (For Jesus had already known from the beginning who those were who did not believe, and who it was who would betray him.) ¹ 

John 6:71

6:71 (Now he said this about Judas son of Simon Iscariot, ²  for Judas, ³  one of the twelve, was going to betray him.) ⁴ 

[6:64]  ¹ sn This is a parenthetical comment by the author.

[6:71]  ² sn At least six explanations for the name Iscariot have been proposed, but it is probably transliterated Hebrew with the meaning “man of Kerioth” (there are at least two villages that had that name). See D. A. Carson, John, 304.

[6:71]  ³ tn Grk “this one”; the referent (Judas) has been specified in the translation for clarity.

[6:71]  ⁴ sn This parenthetical statement by the author helps the reader understand Jesus’ statement one of you is the devil in the previous verse. This is the first mention of Judas in the Fourth Gospel, and he is immediately identified (as he is in the synoptic gospels, Matt 10:4, Mark 3:19, Luke 6:16) as the one who would betray Jesus.