John 6:70

Devil - Slanderer; false accuser.

Have not I chosen you twelve - Have I not, in an especial manner, called you to believe in my name, and chosen you to be my disciples and the propagators of my doctrine! Nevertheless, one of you is a devil, or accuser, enlisted on the side of Satan, who was a murderer from the beginning.

Have not I chosen you twelve? - There is much emphasis in these words. Have not I - I, the Saviour, the Messiah, chosen you in mercy and in love, and therefore it will be a greater sin to betray me? Chosen. Chosen to the apostolic office; conferred on you marks of special favor, and treason is therefore the greater sin. You twelve. So small a number. Out of such a multitude as follow for the loaves and fishes, it is to be expected there should be apostates; but when the number is so small, chosen in such a manner, then it becomes every one, however confident he may be, to be on his guard and examine his heart.

Is a devil - Has the spirit, the envy, the malice, and the treasonable designs of a devil. The word "devil" here is used in the sense of an enemy, or one hostile to him.

6:70 Jesus answered the - And yet even ye have not all acted suitable to this knowledge. Have I not chosen or elected you twelve? - But they might fall even from that election. Yet one of you - On this gracious warning, Judas ought to have repented; is a devil - Is now influenced by one.