The Prophet ﷺ was relating, "While I was sleeping, I saw myself being brought a cup," and he mentioned the rest of it.
حدثنا عبد الرزاق أخبرنا معمر
كان النبي ﷺ يحدث بينما أنا نائم رأيتني أتيت بقدح فذكره
Its isnad is sahih, and it is a repetition of what came before it.