Musannaf Ibn Abi Shayba 3:3555

Waki’ narrated to us, he said: Isra’il narrated to us, from Thawr ibn Abi Fakhitah, from his father, from Ali. He said: It was mentioned to him that what is between Maghrib and Isha is the prayer of the heedless. Ali said: "It is into heedlessness that you have fallen."