Albert Barnes on John 6:70

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 peculiar favour, 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.

(d) "a devil" Jn 13:27