The Messenger of Allah ﷺ said, "Allah has ninety-nine names, one hundred less one. Whoever preserves them will enter Paradise. He is Odd and loves what is odd."
أن رسول الله ﷺ قال: الله تسعة وتسعون اسما مائة إلا واحدة، لا يحفظها أحد إلا دخل الجنة، وهووتر يحب الوتر.
Bukhari related it in the Book of Supplications (6410), and Muslim in the Book of Remembrance and Supplication (2677), both through various routes from Sufyan bin Uyayna, who said, "We memorized it from Abu Zinad, from Araj, from Abu Hurairah," who then narrated it. The wording given is Bukhari's, and Muslim's wording is similar. There are other hadiths with the same meaning mentioned in the Book of Faith.