There was a man at the time of Prophet Muhammad (peace be upon him) named Safi son of Sayyad.
A Strange Man
Safi was a young man who was raised originally from a Jewish family. He was grown to hate Prophet Muhammad (peace be upon him) immensely for no reason.
It was said that Safi was able to tell you what you’re thinking. Prophet Muhammad (peace be upon him) heard about him, and he wanted to find out whether he was really the Antichrist or not.
So he went with Umar towards the village where Safi ibn Sayyad was. And he was sitting down playing with something. Umar tells the story, he says:
Prophet Muhammad was hiding behind the trees trying to come closer to this boy to try to hear what he’s saying. As Prophet Muhammad (peace be upon him) approached Safi very closely, suddenly the boy’s mother saw him and warned her son, “Muhammad is there.”
Safi looked up and stopped talking, and started getting angry.
Prophet Muhammad (peace be upon him) said:
If only his mother didn’t see me, I could have listened for a few more words and I would have known whether he is the Dajjal or not.
Prophet Muhammad (peace be upon him) said to the boy:
I hid something inside of my brain and I want you to try to figure out what it is.
The boy frowned a bit and said:
“Ad-Dukh.”
Prophet Muhammad (peace be upon him) said:
May your power never rise beyond that.
Then he said:
Do you believe that I am the messenger of God?
He replied:
“Only if you believe that I am the messenger of God.”
Prophet Muhammad (peace be upon him) got up and left.
Umar asked about the meaning of dukh and he said it means smoke.
Safi Converted to Islam
Safi grew up in Madinah and he actually embraced Islam, he got married and it is said that he had ten children.
The companions used to avoid him. One day, on their way back from Hajj, a companion of Prophet Muhammad was sitting under a shade of a tree and Safi got his luggage up and sat next to this companion. The companion tried to avoid him and Safi cried.
Then Safi proved that he was not what people thought about him as being the Antichrist. The Antichrist is not a Muslim and he can’t be married and have children.