Jesus, referring to himself as the Son of Man, meaning the Messiah per Daniel 7:13-14 and Psalm 80:17-18, tells his disciples they will long to be with him for he will have left them, but only after he must suffer many things and be rejected by his generation. This was the second time he told them of his coming crucifixion.
During their separation, people will try to deceive them into thinking he has returned or is about to return. Surely, this has happened more than once in my lifetime too. Jesus says pay no attention to them. They are false prophets. No one will need to tell his disciples when he comes, for all will see him in his glory.
When Jesus was on the Mount of Transfiguration, the disciples saw him in his glory. They reported, “As he was praying, the appearance of his face changed, and his clothes became as bright as a flash of lightning.” (Luke 9:29)
Daniel the prophet saw him and reports, “As I looked, thrones were set in place, and the Ancient of Days took his seat. His clothing was as white as snow; the hair of his head was white like wool. His throne was flaming with fire, and its wheels were all ablaze.” (Daniel 7:9)
John the Apostle reported of his appearance in Revelation 1:12-16. “I turned around to see the voice that was speaking to me. And when I turned I saw seven golden lampstands, and among the lampstands was someone “like a son of man,” dressed in a robe reaching down to his feet and with a golden sash around his chest. His head and hair were white like wool, as white as snow, and his eyes were like blazing fire. His feet were like bronze glowing in a furnace, and his voice was like the sound of rushing waters. In his right hand he held seven stars, and out of his mouth came a sharp double-edged sword. His face was like the sun shining in all its brilliance.”
Appearing is such splender will anyone need to tell another, “He is over here. Come and see?” He will be seen by all just as surely as he died and rose from the dead.
