Abû Hurayrah relates that Allah's Messenger (peace be upon him) said: "Allah has ninety-nine names, one hundred less one, whoever comprehends them all will enter Paradise." [Sahîh al-Bukhârî (2737) and Sahîh Muslim (2677)]
In some narrations of this hadîth, these names are enumerated as follows: "He is Allah besides whom there is no God: the Beneficent, the Merciful, the Sovereign, the Holy…" until ninety-nine names are listed.
This additional text is found in Sunan al-Tirmidhî and Sunan Ibn Mâjah with different chains of transmission. However, scholars of hadîth are agreed that this addition is not from the words of Prophet Muhammad peace be upon him).
There are a number of important things this hadîth tells us about our belief in Allah's names:
1. Allah has many names.
Allah says in the Qur'ân: "Say: If the ocean were ink (wherewith to write out) the words of my Lord, the ocean would be used up before the words of my Lord would be exhausted, even if we added another ocean like it to help us." [Sûrah al-Kahf: 109]
Allah also says: "And if all the trees in the earth were pens, and the sea, with seven more seas to help it, (were ink), the words of Allah could not be exhausted. Lo! Allah is Mighty, Wise." [Sûrah Luqmân: 27]
The various modes of Allah's praise, all the numerous aspects of His glory, perfection, greatness, might, and power, are beyond human comprehension. Our minds can never conceive a limit to His nature. Therefore, we should not understand this hadîth to be limiting Allah's names to ninety-nine.
Indeed, it is authentically related from Ibn Mas`ûd that the Prophet (peace be upon him) said, while supplicating his Lord: "I beseech You by every name You have, by which You have named Yourself, or have revealed in Your Book, or taught any of Your creatures, or preserved in the knowledge of the unseen that is with You…" [Musnad Ahmad (3712, 4318), Sahîh Ibn Hibbân (972) and Mustadrak al-Hâkim (1/507)]
Also, in a hadîth describing the Prophet's intercession on the Day of Judgment, the Prophet (peace be upon him) foretells that he will prostrate beneath the Throne, and then Allah will reveal to him words of praise that had never before been taught to anyone. [Sahîh al-Bukhârî (7410) and Sahîh Muslim (193)]
Our Lord has names that He has attributed to Himself. Some of these he has revealed in His Books, like those that are mentioned the Qur'ân. Up to eighty-one names for Allah have been identified in the Qur'ân. Allah has revealed some of His names to a select few of His creatures, like the prophets and the angels.
There are, however, names the knowledge of which Allah has withheld for Himself, names He has taught to no one. This is because Allah cannot be fathomed by His creatures. There are an infinite number of glorious meanings which we as His creatures simply cannot comprehend. His truth is absolute, and His majesty is boundless. His beauty, power, and perfection are without limit. As a consequence, only He can comprehend all of the meanings and names that apply to Him.
As for the ninety-nine names mentioned in the hadîth, these are merely a fraction of His names which have a special significance attached to them. Among what is special about them is that "whoever comprehends them all will enter Paradise."
2. Allah's names are known to us only by way of the revealed texts.
We cannot make up names for Allah. People may certainly extol the praise and glory of their Lord in various ways. There is tremendous creative scope for doing so, as we ca see in the speech of scholars, literary masters, and poets. Indeed, sometimes even those who are illiterate, or uneducated, or new believers come up with the most exquisite and eloquent ways to praise and glorify their Lord, inspired as they are by their deep heartfelt love. This is perfectly alright, since it is part of what it means to communicate about Allah, whose deeds are most worthy of being extolled.
It is a different matter when we are talking about Allah's names. It is impermissible for us to turn what we say about Allah into new names for Him – by which we then call out to Him and invoke Him in our prayers. We can only attribute to Him the names that He has revealed to us in scripture.
This applies even to meanings about Allah that we can ascertain from the Qur'ân. For example, the Qur'ân informs us that Allah speaks and that He declares things. However, it does not give Him names like: "The Speaker" and "The Declarer".
What we have as Allah's names are limited to what is cited in the Qur'ân and Sunnah in the form of names, like: "The Creator, The Former, The Fashioner, The King, The Holy, The Peace, The Mighty, The Wise, The Sublime, The Great…"
I recall reading in Sheikh Hasan al-Banna's Islamic Creed that he rejected the idea of naming Allah: "The Engineer of the Universe". It is good that he criticized this tendency.
3. The meaning of the word "comprehend" is multi-faceted.
In the statement "Allah has ninety-nine names, one hundred less one, whoever comprehends them all will enter Paradise" the word encompasses a number of concepts:
First, it conveys the meaning of simply knowing these names and committing them to memory. A number of scholars have made efforts to deduce these names from the Qur'ân and authentic Sunnah and to enumerate them. These scholars including al-Zajjâj, Ibn Mandah, Ibn Hazm, al-Ghazâlî, Ibn al-`Arabî, al-Qurtubî, and among contemporary scholars al-`Uthaymîn and `Umar al-Ashqar.
Knowing these names is certainly part of what it means to "comprehend" them. It is certainly a virtue for a Muslim to know these names, invoke them, and call upon Allah with them. It is a good idea, therefore, for a Muslim to write these names down somewhere conspicuous for easy reference, like in the care or in a room as a reminder and to facilitate their memorization.
Secondly, part of "comprehending" Allah's names is to have knowledge of their meanings. These names are not mere symbols or abstract signifiers of Allah. Neither are they obscure and difficult to comprehend. They are clear Arabic words which are intended to be readily understood. Therefore, it is essential for a Muslim to at least read a short book that explains the meanings of Allah's names.
When we invoke Allah by His names, the different words we utter should have meaning for us. We should not be simply uttering by rote a string of syllables that we do not understand. Understanding Allah's names is in itself a great blessing which elevates our hearts, our minds, and our spirits.
Thirdly, we should invoke Allah by these names when we beseech Him in supplication. Allah says: "Allah's are the most beautiful names, so call on him by them; and leave the company of those who His names in profanity." [Sûrah al-A`râf: 180]
Fourthly, we should recall the meanings of Allah's names to mind. The worst thing that we are afflicted with in life is heedlessness of Allah and becoming totally immersed in our material concerns. The best medicine for our hearts is to remain aware of Allah's greatness.
We should strive to bring ourselves to ever higher levels of awareness and faith, until we attain the level the Prophet describes as: "to worship Allah as though you see him."