Theophylact of Ohrid

See how in his blindness he thought to deceive Christ by the kiss, so as to be looked upon by Him as His friend. But if thou wert a friend, Judas, how didst thou come with His enemies? But wickedness is ever without foresight. And as soon as he was come, he goeth straightway to him, and saith, Master, master; and kissed him.

Catena Aurea by Aquinas ↗

Bede

Now the betrayer had given them a sign, saying: Whomsoever I shall kiss, etc. Indeed, an impudent and wicked confidence, to call Him Master and to give a kiss to Him whom he was betraying. However, he still had something of the disciple's shame, since he did not openly hand Him over to the persecutors, but by the sign of a kiss. …

On the Gospel of Mark ↗