Did Muhammad make a false prophecy that the end of the world would come within a living boy's lifetime?

The report is not a failed prediction that the universe would end in a child's lifetime. Read in its wording, context, and the Prophet's own teaching, it refers to the "hour" of that generation - their death and disappearance - not the final Day of Resurrection.

The strongest form of the criticism

The objection has force if the hadith is read like this: someone asked the Prophet (PBUH) when the final Hour would occur; he pointed to a young boy and said it would arrive before that boy became old; the boy died long ago, while the world remains. On that reading, it would be a dated prophecy that failed.

That is why the issue turns on what the Prophet (PBUH) actually meant by "Hour" in this setting. A single English rendering can make the report sound simpler than it is.

What the report actually says

In Sahih al-Bukhari, the wording is not merely "the Hour" in the abstract, but "your Hour" - addressed to the people present:

"If this boy lives, he will not reach old age before your Hour comes upon you."

Sahih al-Bukhari 6511

Sahih Muslim transmits the same meaning. In another narration, Aisha described that Bedouins would ask the Prophet (PBUH) about the Hour, and he would look at the youngest among them and say that if he lived, he would not grow very old before "your Hour" came. The early explanation given in the report is that he meant their death.

"He meant their death."

Sahih Muslim 2953

This is not a forced escape. Arabic, like English, can use "hour" for a person's appointed time: "his hour has come." The Quran also uses ajal - an appointed term - for nations and individuals. So the Prophet (PBUH) was reminding them that, for them practically, the meeting with Allah was near. Whether the cosmos ends tomorrow or after many ages, each person's judgment begins with death.

Why it cannot mean he gave the final date

The Quran repeatedly teaches that the exact time of the final Hour is known only to Allah:

"They ask you about the Hour: when will it arrive? Say: Its knowledge is only with my Lord. None will reveal it at its time except Him."

Quran 7:187

And in the famous hadith of Jibril, when the Prophet (PBUH) was asked about the Hour, he answered:

"The one who is asked about it knows no more than the one who asks."

Sahih al-Bukhari and Sahih Muslim

So to interpret the boy report as "the world will end before this child grows old" would make the Prophet (PBUH) contradict the Quran and his own clear statement that he did not know the date. Sound interpretation does not take an ambiguous phrase against explicit doctrine, especially when the narration itself says "your Hour."

What this does and does not prove

It does prove that the Prophet (PBUH) taught urgency: do not treat the Hereafter as distant, because your own end is close. It also fits the historical reality that the people addressed died within a normal human lifetime.

It does not prove that he set a date for the end of the world. Therefore the appeal to Deuteronomy 18:22 misses the point: that criterion would apply if an actual prediction had failed. Here, the strongest reading of the Arabic and the hadith context is that the prediction concerned the death of that generation, not the final destruction of the world.

The report is a warning, not a calendar. The Prophet (PBUH) did not give people the date of the Hour; he turned their attention to the hour they could not avoid - their own meeting with Allah.