Abu Huraira reported God’s messenger as saying, “God had ninety-nine names, one short of a hundered. He who retains them in his memory* will enter paradise.” A version has, “And He is One. He loves what is single.”
*The Arabic is ahsaha, a word which has different meanings. Besides the meaning above can mean to number, to reach the last number, to understand, to attain comprehensive knowledge.
(Bukhari and Muslim.)