Yes, if someone were to argue with you about a person’s greatness or grandeur, and you said, “If your companion is great, then Allah is greater than him,” there is nothing wrong with this. It is like His saying, exalted is He:
“They plan, and Allah plans. And Allah is the best of planners.” [al-Anfal 8:30]
And like His saying:
“Is Allah better, or what they associate with Him?” [al-Naml 27:59]
But when offering unrestricted praise, it should not be qualified by anything.
His statement, “greatly so”: this is a circumstantial qualifier referring to the implicit pronoun in “Most Great,” because “Most Great” is an elative form—contrary to those who say that “Allah is Most Great” means “Allah is great,” that is, in the sense of an active participle. This is mistaken, because the active participle conveys perfection less fully than the elative form. The elative precludes equality between that which is deemed superior and that over which it is deemed superior in the quality in question, whereas the active participle does not preclude this. Thus, if you say, “Zayd is knowledgeable,” this does not rule out ‘Amr being equal to him in knowledge, if he too is knowledgeable. But if you say, “Zayd is more knowledgeable than ‘Amr,” it indicates that he is not equal to him, and that Zayd is more knowledgeable.
Some scholars, may Allah have mercy on them, interpret “Allah knows best,” “Allah is Most Great,” and similar expressions as active participles, out of caution lest there be a comparison of superiority between the Creator and the created. There is no doubt that this is mistaken. Comparison of superiority does occur, but it does not entail equality between that which is superior and that over which it is superior; rather, it does not imply this at all—unlike the active participle.
His statement, “and all praise is due to Allah, abundantly”: praise means ascribing perfection to the one praised; it does not mean repeatedly ascribing perfection to him, for repeated praise is what is called commendation. Allah distinguished between the two in the sacred hadith, when He says: “When he—that is, the worshipper—says, ‘All praise is due to Allah, Lord of all worlds,’ He says:”