Ba'al Shem Tov, Noach 3/בעל שם טוב על התורה·נח ג׳

1I heard from my Master that someone asked Nachmanidies, “What is considered the service of G‑d?” and he answered, “Whatever gives delight and joy, combined with fear.”Toldos Yaakov Yosef, Mishpotim, p. 70b