Musannaf Ibn Abi Shayba 3:892

Isma'il ibn Ibrahim narrated to us, from Ibn Jurayj, from Ibn Abi Mulayka, Umm Salama said: "The Messenger of Allah (peace and blessings of Allah be upon him) was more hastening for the Dhuhr (prayer) than you, and you are more delaying for the Asr (prayer) than him."