The Son of Man was a title Jesus applied to himself. As such, most New Testament mentions of this phrase are found in the four gospels.
Jesus used this phrase euphemistically. His close followers likely understood it to mean the Son of God, yet his adversaries (the Jewish leaders) were in the dark.
It’s likely that had he publicly called himself the Son of God, he would have been quickly executed for blasphemy. In fact, he was killed only hours after he admitted to being the Son of God (Luke 22:70).
The phrase son of man is also found in the Old Testament, mostly in the book of Ezekiel, seemingly as a pet nickname that God called Ezekiel.
However, Daniel records that “In my vision at night I looked, and there before me was one like a son of man, coming with the clouds of heaven” (Daniel 7:13).
Jesus likely took his title, the Son of Man, from this verse.
Key verse about Son of Man: Then the word of the Lord came to him: “This man will not be your heir, but a son who is your own flesh and blood will be your heir.” He took him outside and said, “Look up at the sky and count the stars—if indeed you can count them.” Then he said to him, “So shall your offspring be.” (Genesis 15:3-5, NIV)
A lifelong student of the Bible, Peter DeHaan, PhD, wrote the 1,000-page website ABibleADay.com to encourage people to explore the Bible. His main blog and many books urge Christians to push past the status quo and reconsider how they practice their faith in every area of their lives.