Son of Man is from the Old Testament Book of the Prophet Daniel
As the visions during the night continued, I saw coming with the clouds of heaven
One like a son of man.
When he reached the Ancient of Days
and was presented before him,
He received dominion, splendor, and kingship;
all nations, peoples and tongues will serve him.
His dominion is an everlasting dominion
that shall not pass away,
his kingship, one that shall not be destroyed.
(Daniel 7:13-14)
First century Jews were very knowledgeable about their scriptures and many would have recognized the reference clearly. When Jesus refers to himself as the Son of Man, he is teaching those around him of his idenity as a king, and that all people will serve him, and that his kingdom will last forever.
Son of Man is also a reference to Ezekiel 12 where the phrase is mentioned six times. It is worth reading the whole chapter, but an importan passage is the one below.
Thus the word of the LORD came to me: Son of man, you live in the midst of a rebellious house; they have eyes to see but do not see, and ears to hear but do not hear, for they are a rebellious house.(Ezekiel 12:1-2)
Using a rabbinical teaching technique, Jesus makes oblique and not so oblique references to this passage several times in the Gospels.
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And if you are willing to accept it, he is Elijah, the one who is to come. Whoever has ears ought to hear. (Matthew 11:14-15)
He said to them, “Is a lamp brought in to be placed under a bushel basket or under a bed, and not to be placed on a lampstand? For there is nothing hidden except to be made visible; nothing is secret except to come to light. Anyone who has ears to hear ought to hear.” (Mark 4:21-23)*
This is Jesus way of saying, “I am the Son of Man, and if you do not pay attention to what I just said then you are rebellious.” He even asks his disciples point-blank if they are rebelling against him.
When he became aware of this he said to them, "Why do you conclude that it is because you have no bread? Do you not yet understand or comprehend? Are your hearts hardened? Do you have eyes and not see, ears and not hear?" (Mark 8:17-18)
Again, it is Jesus the Rabbi using a rabinnical teaching technique. He uses the question “Do you have ears but not hear?” to bring to the mind of his disciples the “Rebellious house” in Ezekiel and as a way to ask them if they are rebelling against him. He uses phrases like “Son of Man” to refer to himself and in so doing he brings whole passages and themes in Olt Testament scripture to light, indicating his own identity through a few small words in a way which a long, drawn out explanation could not. This is classic rabinnical teaching. It is truly sublime because Jesus not only uses these phrases beautifully, but as Jesus is God, he himself is the primary author of these phrases.
The Holy Father, Blessed Pope John Paul II the Great gave a brief reflection on the topic of “
Jesus Christ, Son of Man”
-Tim-