This and similar examples demonstrate how even the best and most complete of creation after the Messenger needed to follow his guidance, learn from him, and discern the truth through what he brought. What, then, of someone who claims that his words concerning knowledge of Allah and the Last Day contain no knowledge, guidance, or understanding from which people of sound intellect—who are below ‘Umar and those like him—can benefit?

Allah Most High has said:
“Mankind was one community; then Allah sent the prophets as bearers of glad tidings and warnings, and sent down with them the Scripture in truth, to judge between people concerning their differences.”
Al-Nisā’: 59.

How can words and discourse containing no knowledge or guidance beneficial to people of sound intellect judge between people in matters of disagreement and dispute?

These heretics among the later Peripatetic philosophers and their followers claim that revealed laws cannot be cited as evidence in such matters. But how can people appeal to something that cannot serve as evidence to resolve their disagreements?

What disagreement could be greater than their disagreement over the greatest matters: knowledge of Allah Most High and the Last Day? Especially since it is well known that genuine disagreement concerns theoretical matters and propositions concerning goodness, which admit of neither abrogation nor change. As for practical matters that admit of abrogation and change—as for practical matters that admit of abrogation—these vary even within a single revealed law, so how much more across different revealed laws?