Allah's Secret Within Creation

The essence (meaning the reality and the essence) of divine decree is Allah's secret within creation.

It is something only Allah knows.

No intimate angel or prophetic emissary has ever been privy to it.

So no prophet has known all that Allah knows. When the Prophet (peace be upon him) is spoken of as having a great deal of knowledge, and some people say he had all knowledge: being ʿālim al-ghayb is very relative. There are many things of the unseen that the Prophet (peace be upon him) was given knowledge of, over and above the knowledge of the other prophets. The Prophet (peace be upon him), after Allah (swt), has the most knowledge. But it is very wrong to say that the Prophet (peace be upon him) has the same knowledge as Allah. Even Mawlānā Aḥmad… The problem is simply that there are others who might say that. But that is an opinion which would be a serious problem: to say that he has the same knowledge as Allah, because Allah's knowledge is just so vast.

Even al-Bājūrī says: wa lam yakhruj al-Nabiyyu ṣallā Allāhu ʿalayhi wa sallam min al-dunyā ḥattā aṭlaʿahu Allāhu taʿālā ʿalā jamīʿi mā abhamahu ʿanhu min al-rūḥi wa ghayrihā, mimmā yumkinu al-bashar bihi, lā ʿalā jamīʿi maʿlūmātihi taʿālā. He says that the Prophet (peace be upon him) did not leave this dunyā until Allah (swt) had made him privy to all that which He had concealed from him, about the rūḥ and other things which are possible to be known, possible to be known by a human being. Not (he makes this clear) all of His knowledge. Wa illā lazima musāwātu al-ḥādithi li-l-qadīm: otherwise, the problem would be that the ḥādith, the created being, which the Prophet (peace be upon him) is, would become the same as and equal to the eternal being, Allah (swt). So he makes that very clear.