Arabic hadith text
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ يَحْيَى بْنِ سَعِيدٍ، أَنَّ عُمَرَ بْنَ عَبْدِ الْعَزِيزِ، غَدَا يَوْمَ عَرَفَةَ مِنْ مِنًى فَسَمِعَ التَّكْبِيرَ عَالِيًا فَبَعَثَ الْحَرَسَ يَصِيحُونَ فِي النَّاسِ أَيُّهَا النَّاسُ إِنَّهَا التَّلْبِيَةُ ‏.‏
Translation

Yahya related to me from Malik, from Yahya ibn Said, that Umaribn Abd alAziz was once going from Mina (to Arafa) on the day of Arafaand heard the takbir being said loudly, so he sent the guard to shoutout to the people, "O people, you should be saying the talbiya."