Abdullah bin Umar reported,
The Prophet ﷺ stood between the Jamarat on the Day of Sacrifice during the pilgrimage he performed and asked, "What day is this?"They replied, "This is the Day of Sacrifice."He said, "This is the day of the greatest pilgrimage."
Azami 5246
Sahihعن ابن عمر
أن النبي ﷺ وقف يوم النحر بين الجمرات الحجة التي حج، فقال: أي يوم هذا؟ قالوا: هذا؟ قالوا: يوم النحر. قال: هذا يوم الحج الأكبر.
Reported by Abu Dawud (1945), Ibn Majah (3058), who both graded it sahih, by Hakim (2/331), and by Bayhaqi (5/139), from the hadith of Hisham bin Ghaz, who said, "I heard Nafi narrating from Ibn Umar," and he mentioned it. The wording given is that of Abu Dawud. The wording of Ibn Majah and Hakim is longer than this, for both of them mentioned the Prophet's ﷺ sermon in full. Bukhari (1742) related it in suspended form (mualaq) from Hisham bin Ghaz.Hakim said, "This is a hadith sahih in its chain of transmission, though the two of them (Bukhari and Muslim) did not report it with this wording. Most of this text is found in the Sahihayn except for his statement, 'The day of the greater Hajj is the day of sacrifice.' For there are various sayings about this from the companions and the successors 
, who differed concerning it. Some of them said it is the Day of Arafah, and some of them said it is the day of sacrifice."Hisham bin Ghaz is al-Jarashi al-Shami, and he is trustworthy. Ibn Main deemed him trustworthy, and Imam Ahmad said, "His hadith is sound (salih al-hadith)."