Albert Barnes Commentary John 13:20

"Verily, verily, I say unto you, he that receiveth whomsoever I send receiveth me; and he that receiveth me receiveth him that sent me." — John 13:20 (ASV)

He that receiveth, and so forth. This sentiment is found in the instructions which Jesus gave to his disciples in Matthew 10:40. Why he repeats it at this time cannot now be known. It is certain that it is not closely connected with the subject of his conversation. Perhaps, however, it was to show how intimately united he, his Father, his apostles, and all who received them were.

Those who received them received him, and those who received him received God. So he who betrayed him, betrayed, for the same reason, God. Hence Judas, who was about to betray him, was also about to betray the cause of religion in the world, and to betray God and his cause.

Everything pertaining to religion is connected together. A man cannot dishonor one of the institutions of religion without injuring all; he cannot dishonor its ministers or the Savior without dishonoring God. And this shows that one prominent ground of the Savior's solicitude was that his Father might be honored, and one source of his deep grief at the treason of Judas was that it would harm the whole cause of religion in the world.