The argument identifies a real limitation in one kind of apologetic claim: these prophecies do not, by themselves, prove omniscience. But it does not follow that a prophecy about lands known to the Arabs is merely human, nor does the Quran or Sunnah present the list of early conquests as an exhaustive map of the earth.
The objection in its strongest form
A thoughtful critic can argue that Persia, Byzantium, and Yemen were the obvious powers and regions around Arabia. An ambitious seventh-century leader could reasonably expect his movement to spread into nearby territories. If Muhammad (PBUH) had divine knowledge, the critic asks, why did he not name places such as the Americas or Australia, which were unknown to his audience?
That is a fair challenge to an exaggerated argument: the mere fact that Islam reached neighboring lands is not, on its own, a miracle. Nor does every report about future victories have the same evidential force. Some refer to events near the first Muslim community, while others describe broader developments over time.
What the prophecy actually claims
The relevant report in Sahih Muslim does not say, "Islam will conquer only the lands surrounding Arabia." It describes a vision of the earth's east and west being shown to the Prophet (PBUH), followed by the promise that his community's dominion would reach what was shown to him:
"Allah gathered the earth for me, and I saw its eastern and western limits. The dominion of my community will reach as far as was gathered for me from it."
Sahih Muslim 2889
This is a claim about extraordinary geographical expansion, not a demand that the Prophet list every distant continent. In ordinary speech, saying that a movement will spread from east to west does not mean that it has mentioned every island or named every country. The same is true of references to Rome, Persia, and Yemen: they identify major and relevant theaters of history, not the full boundary of Islam's future reach.
Why omission is not disproof
Divine knowledge does not require every prophecy to display the most obscure fact available. Prophecy is communication, not a geography examination. A prediction is often given in terms meaningful to its first hearers and connected to their duties, hopes, and trials.
The Quran itself presents Muhammad's mission as universal:
"We have not sent you except to all humanity, as a bearer of good news and a warner."
Quran 34:28
It also describes the believers' promised security and establishment without giving a complete political atlas:
"Allah has promised those of you who believe and do good that He will surely make them successors in the land."
Quran 24:55
What the argument does and does not establish
It does establish that conquest reports about nearby powers should not be oversold as standalone proof of omniscience. It does not establish that Muhammad (PBUH) lacked divine knowledge. That conclusion would require showing a genuine contradiction or false prediction, not merely that a prophecy omitted places it had no reason to name. Considered with the Quran's universal claim, the unusually rapid expansion of the early community, and the wider body of revelation, these reports remain evidence - though not a self-sufficient proof detached from everything else.