He informed him that while Umar was delivering a sermon, he mentioned it.
حدثنا عبد الصمد حدثني أبي حدثنا الحسين المعلم حدثنا يحيى أخبرني أبو سلمة أن
أخبره أن عمر رضي الله عنه بينا هو يخطب فذكره
Its isnad is sahih, and it is a repetition of the one before it.