ما الفرق بين الصلاة على النبي والصلاة للنبي؟

We do not find a difference in meaning between the phrases "الصلاة عليك" (salutations upon you) and "الصلاة لك" (salutations for you), although the former is more common. Both have been mentioned together in the Hadith of Ubayy ibn Ka'b: "Indeed, I make abundant supplications (salawat) upon you, so how much of my supplications should I dedicate to you?"