Al-Bukhaari (2736) and Muslim (2677) narrated from Abu Hurayrah (may Allah be pleased with him) that the Prophet (blessings and peace of Allah be upon him) said: Allah has ninety-nine names, one hundred less one. Whoever learns them by heart will enter Paradise.
Leaning by heart, which is mentioned in the hadeeth, implies the following:
1. Memorising them
2. Understanding their meaning
3. Acting in accordance with the meanings. So if a person knows that He is One, he does not associate anything else with Him. If he knows that He is the Provider (ar-Razzaaq), he does not seek provision from anyone other than Him. If he knows that He is Most Merciful (ar-Raheem), then he does acts of obedience and worship that are the means of attaining this mercyâ¦ and so on.
4. Calling upon Him by these names, as He, may He be glorified and exalted, says (interpretation of the meaning): And (all) the Most Beautiful Names belong to Allah, so call on Him by them' [al-Araaf 7:180]. So he might say: O Most Merciful (Ya Rahmaan), have mercy on me; O Oft-forgiving (Ya Ghafoor), forgive me; O Accepter of repentance (Ya Tawwaab), accept my repentance, and so on.
Shaykh Muhammad ibn Saalih al-Uthaymeen said: Learning them by heart does not mean writing them down on a piece of paper then repeating them until one has memorised them. Rather what it means is:
Firstly: learning how to pronounce the names
Secondly: understanding their meanings.
Thirdly: worshipping Allah in accordance with what they signify, which involves two things:
(i) Calling upon Allah by them, because He, may He be exalted, says (interpretation of the meaning): â¦ so call on Him by them [al-Araaf 7:180], to that they may become a means of attaining what you seek, so choose a name that is appropriate to what you seek. When asking for forgiveness, say: O Oft-forgiving (Ya Ghafoor), forgive me. It is not appropriate to say: O You Who are stern in punishment (Ya Shadeed al-Iqaab), forgive me; rather that is more akin to mockery. What you should say (if you call upon Allah by this name) is: Save me from Your punishment.
(ii) In your acts of worship you should do is what is implied by these names. What is implied by the name ar-Raheem (Most Merciful) is mercy, so do righteous deeds that will bring the mercy of Allah. This is what is meant by learning them by heart; if it is done like this, then it deserves to be the price of admission to Paradise. End quote.
Majmoo Fataawa wa Rasaa'il Ibn Uthaymeen, 1/74
And Allah knows best.
Reproduced from Islam QA