And similarly, I say: Its origin is "O Allāh," where the vocative particle was omitted and replaced with the letter "mīm" for grandeur and emphasis. It is not preceded by "yā," so it is not said "yā Allāhumma" except rarely in poetry, as Ibn Mālik said: "Most commonly, 'Allāhumma' is used with the substitution, and 'yā Allāhumma' is rare in verse. Then, its common usage is in supplication, and thus the predecessors said: 'Allāhumma' is the essence of supplication." Some have said: The "mīm" in the phrase "Allāhumma" contains ninety-nine names of Allāh, the Exalted. Some have explained it by saying that the "mīm" serves as a sign of plurality, because you say "ʿalayhi" for the singular and "ʿalayhim" for the plural. Thus, the "mīm" in this context is like the "wāw" indicating plurality in "ḍarabū" and "qāmū." Therefore, it was added to the end of Allāh's name to indicate and signify that this name encompasses all of Allāh's names. So when the supplicant says "Allāhumma," it is as if he is saying: "O Allāh, who possesses the most beautiful names." He said: And because it encompasses all of Allāh's most beautiful names and attributes, it cannot be described, as they have all been gathered in it. This is evidence for what Sībawayh said in prohibiting its description. End of statement.