Ali b. Abi Talib (a.s.) passed by a group of people, which included Salman.

Salman said to the people – Stand up and hold on to Ali b. Abi Talib (a.s.). I swear to Allah that no one can tell you about the secrets of the Prophet (s.a.w.a.) except Ali.
Al-Amaali p 138, 354 Al-Amaali v 1 p 124 Al-Amaali p 440