Musnad Abu Ya'la al-Mawsili 128:30

Suwayd ibn Sa'id narrated to us, Marwan ibn Mu'awiyah narrated to us, from 'Isa ibn Abi 'Isa—and he is not al-Aswari—from Anas ibn Malik, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "The master of your condiment is salt."