Mustadrak al-Hakim — Hadith 1940

It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him), giving counsel to Sayyiduna Salman al-Khayr (al-Farisi) (may Allah be pleased with him), said: "O Salman! The Messenger of Allah wishes to give you words with which you may ask the Most Merciful, turn to Him in longing, and supplicate by them day and night. Say: 'Allahumma inni as'aluka sihhatan fi iman, wa imanan fi husni khuluq, wa najahan yatba'uhu falah, wa rahmatan minka wa 'afiyah, wa maghfiratan minka wa ridwana' (O Allah, I ask You for health and well-being along with faith, for complete faith along with good character, for success followed by prosperity, and for mercy, well-being, forgiveness and Your good pleasure from You)."
This hadith has a sahih (authentic) chain, but the two Shaykhs (Bukhari and Muslim) did not record it.