The Prophet ﷺ said, "The month is like this, like this, and like this," ten, ten, and nine once.
حدثنا معاوية بن عمرو حدثنا زائدة عن إسماعيل
عن النبي ﷺ قال الشهر هكذا وهكذا عشر وعشر وتسع مرة
Its isnad is sahih, and it is a repetition of what came before it.