Matthew
Matthew 26:49ESV·traditional attribution

And he came up to Jesus at once and said, “Greetings, Rabbi!” And he kissed him.

John Calvin Reformed @genevareformer

49. Hail, Rabbi. I have no doubt that Judas, as if trembling for his Master’s danger, pretended by these words to have some feeling of compassion; and, accordingly, in Mark a pathetic repetition is expressed, “Il y a une repetition comme d’un homme parlant de grande affection;” — “there is a repetition, as if by a man who spoke from strong feeling.” Rabbi, Rabbi.

John Gill Reformed Baptist @doctorgill

And Jesus said unto him, friend,.... Not in an ironical and sarcastic way, but because he pretended to be his friend, by saluting and kissing him, in the manner he had done; or rather, because Christ had always used him as his friend, his familiar friend, who had been of his councils, and had ate at his table; and therefore this carried in it something...

Albert Barnes Presbyterian @notesbybarnes

Verse 49. Hail, Master. The word translated hail, here means, to rejoice, to have joy; and also to have cause of joy. It thus expresses the joy which one friend has when he meets another, especially after an absence. It was used by the Jews and Greeks as a mode of salutation among friends.