Musannaf Ibn Abi Shayba 38:21

Yahya ibn Adam narrated to us, Abu al-Ahwas narrated to us, from Khalid ibn Alqama, from Abd Khayr, who said: A tent was pitched between the two armies on the day of the Camel for three days. Ali, al-Zubayr, and Talha would come to it and mention in it what Allah willed. Until, when it was the third day at the decline of the sun, Ali lifted the side of the tent, then ordered the fighting. So we walked toward one another and we thrust with spears until, if a man had wished to walk upon them, he could have walked. Then the swords took us, and I did not liken it to anything except the house of al-Walid.