During Muhammad's prophetic career, there was a young man named Saf Ibn Sayyad, who challenged Muhammad, claimed to be a prophet, and whom Muhammad thought could be the Dajjal:

Sahih al-Bukhari 3055

Narrated Ibn 'Umar:
Umar and a group of the companions of the Prophet (ﷺ) set out with the Prophet to Ibn Saiyad. He found him playing with some boys near the hillocks of Bani Maghala. Ibn Saiyad at that time was nearing his puberty. He did not notice (the Prophet's presence) till the Prophet (ﷺ) stroked him on the back with his hand and said, "Ibn Saiyad! Do you testify that I am Allah's Messenger (ﷺ)?" Ibn Saiyad looked at him and said, "I testify that you are the Apostle of the illiterates."

Then Ibn Saiyad asked the Prophet. "Do you testify that I am the apostle of Allah?" The Prophet (ﷺ) said to him, "I believe in Allah and His Apostles." Then the Prophet (ﷺ) said (to Ibn Saiyad). "What do you see?" Ibn Saiyad replied, "True people and false ones visit me." The Prophet said, "Your mind is confused as to this matter." The Prophet (ﷺ) added, "I have kept something (in my mind) for you." Ibn Saiyad said, "It is Ad-Dukh (smoke)." The Prophet (ﷺ) said (to him), "Shame be on you! You cannot cross your limits." On that 'Umar said, "O Allah's Messenger (ﷺ)! Allow me to chop his head off." The Prophet (ﷺ) said, "If he should be him (i.e. Ad-Dajjal) then you cannot overpower him, and should he not be him, then you are not going to benefit by murdering him."

This is also narrated in Sahih Muslim 169d, 2924a-b, 2925, 2930a-c, 2931.

Above, we see that:

• Ibn Sayyad was young here - not even adolescent
• Muhammad asks him to testify that Muhammad is the apostle of Allah
• Ibn Sayyad calls Muhammad "The Apostle of the illiterates", and asks him to testify that he is the apostle of Allah
• Muhammad asks Ibn Sayyad to read his mind. Ibn Sayyad says he sees smoke, i.e., Muhammad was thinking of smoke to conceal what was in his mind, which some say was a superstition at the time
• Umar, characteristically, wants to kill someone, Ibn Sayyad in this case
• Muhammad forbids killing him on the basis that he may be the Dajjal

Clearly, Muhammad was open to the fact that this kid may have been the Dajjal, which is more evidence toward the fact that he taught and believed that the Last Hour was imminently near.

Later on, in a rather hilarious scene, Muhammad sneaks up on Ibn Sayyad while he is laying down, and peers at him from behind some date-palm trees. Ibn Sayyad's mother catches him, and calls out to Ibn Sayyad, foiling Muhammad's endeavor:

Sahih al-Bukhari 3056-57

Narrated Ibn Umar:
(Later on) Allah's Messenger (ﷺ) (once again) went along with Ubai bin Ka'b to the garden of date-palms where Ibn Saiyad was staying. When the Prophet entered the garden, he started hiding himself behind the trunks of the date-palms as he wanted to hear something from the Ibn Saiyad before the latter could see him. Ibn Saiyad was lying in his bed, covered with a velvet sheet from where his murmurs were heard. Ibn Saiyad's mother saw the Prophet (ﷺ) while he was hiding himself behind the trunks of the date-palms. She addressed Ibn Saiyad, "O Saf!" (And this was his name). Ibn Saiyad got up. The Prophet (ﷺ) said, "Had this woman let him to himself, he would have revealed the reality of his case." Then the Prophet (ﷺ) got up amongst the people, glorifying Allah as He deserves, he mentioned Ad-Dajjal, saying, "I warn you about him (i.e. Ad-Dajjal) and there is no prophet who did not warn his nation about him, and Noah warned his nation about him, but I tell you a statement which no prophet informed his nation of. You should understand that he is a one-eyed man and Allah is not one-eyed."

This is also narrated in Sahih Muslim 169d, 2930a-c, 2931.

Why does the "Messenger of Allah", the "Seal of the Prophets", need to spy on a kid to figure out if he is the Dajjal? Isn't he receiving revelation from God? Isn't he meeting with the Angel Gabriel? Wouldn't Gabriel have told him if this was the Dajjal, instead of leaving him to sneak behind some trees, to be caught by a boy's mother? Why didn't Muhammad pray to Allah for answers?

Eventually, as we read in many narrations (Sahih Muslim 2927a-c, 2929), Muhammad's behavior made the people all think that Ibn Sayyad was the Dajjal, which caused him to consider suicide:

Sahih Muslim 2927c

Abu Sa`id al-Khudri reported:
We came back after having performed Pilgrimage or `Umra and lbn Sa'id was along with us. And we encamped at a place and the people dispersed and I and he were left behind. I felt terribly frightened from him as it was said about him that he was the Dajjal. He brought his goods and placed them by my luggage and I said: It is intense heat. Would you not place that under that tree? And he did that. Then there appeared before us a flock of sheep. He went and brought a cup of milk and said: Abu Sa`id, drink that. I said it is intense heat and the milk is also hot (whereas the fact was) that I did not like to drink from his hands or to take it from his hand and he said: Abu Sa`id, I think that I should take a rope and suspend it by the tree and then commit suicide because of the talks of the people, and he further said.

Abu Sa`id he who is ignorant of the saying of Allah's Messenger (ﷺ) (he is to be pardoned), but O people of Ansar, is this hadith of Allah's Messenger (ﷺ) concealed from you whereas you have the best knowledge of the hadith of Allah's Messenger (ﷺ) amongst people? Did Allah's Messenger (ﷺ) not say that he (Dajjal) would be a non believer whereas I am a believer? Did Allah's Messenger (ﷺ) not say he would be barren and no child would be born to him, whereas I have left my children in Medina? Did Allah's Messenger (may peace upon him) not say: He would not get into Medina and Mecca whereas I have been coming from Medina and now I intend to go to Mecca? Abu Sa`id said: I was about to accept the excuse put forward by him. Then he said: I know the place where he would be born and where he is now. So I said to him: May your whole day be spent.

From the above, notice:

• It's a common saying that Ibn Sayyad is the Dajjal
• This slander, perpetuated by Muhammad, causes him to despair of life
• Ibn Sayyad points out that Muhammad taught that the Dajjal would be a childless unbeliever who cannot enter Mecca or Medina (which is supported by many other narrations), yet he was a Muslim, with children, who had entered Medina

In light of Muhammad's own revelations, this person literally could not be the Dajjal. Did Muhammad ever tell everyone to leave him alone? Did Muhammad ever publicly vindicate him? No, rather, Muhammad was responsible for the whole situation, and perpetuated the rumors with his antics.

Conclusion

Could the contrast between Muhammad and Jesus Christ be made any clearer than in an account like this? Does anyone reading this think that the Lord Jesus would have had to spy on a child, or challenge him to read His mind, or falsely insinuate that he would be the Antichrist? Of course not. Muhammad was acting like a superstitious Pagan, without divine revelation, and as a result, he ruined the life of an innocent person.