Musnad Ahmad 27:1275

Abdullah ibn al-Walid narrated to us, Sufyan narrated to us, from Layth and Ibrahim ibn al-Muhajir, from Mujahid, from Ibn Umar, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Give permission to the women at night to the mosques, [while they are] *tafilat* (unperfumed)." Layth is the one who mentioned "tafilat."