Mishkat al-Masabih #2383

Anas told of a man who came to the Prophet and asked him which supplication was most excellent. To this he replied, "Ask your Lord for health and for security from evil in this world and the next." He came to him on the following day, asked the same question, and received a similar reply. Then when he came on the third day he received a similar reply with this addition, "If you are given health and security from evil in this world and the next, you have attained felicity." Tirmidhi and Ibn Majah transmitted it, Tirmidhi saying this is a hasan tradition whose isnad is gharib.