It is narrated from Sayyiduna Ma'mar bin Abdullah al-Adawi (may Allah be pleased with him); he said: The Prophet (peace and blessings be upon him) sent me to announce among the people at Mina: "The days of Tashriq are days of eating and drinking."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 18217