Allah ordered His Prophet [s] to inform the people of this designation at a time of crowded populous so that all could become the narrators of the tradition, while they exceeded a hundred thousand.
Narrated by Zayd b. Arqam: Abu al-Tufayl said: "I heard it from the Messenger of Allah [s], and there was no one (there) except that he saw him with his eyes and heard him with his ears."
source : http://www.al-islam.org
