Musnad Ahmad 27:652

Abdullah ibn al-Walid narrated to us, Sufyan narrated to us, from al-A’mash and Layth, 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 to go to the mosques at night." His son said: "We will not give them permission, lest they take it as a means for mischief." He (Ibn Umar) said: "I make you hear me saying: 'The Messenger of Allah (peace and blessings of Allah be upon him) said,' and you say: 'No'?"