Musannaf Ibn Abi Shayba 3:5231

Abu Usama narrated to us, from Ubayd Allah ibn Umar, from Nafi, from Ibn Umar, who said: There was a wife of Umar who would attend the dawn and evening prayers in congregation at the mosque. It was said to her, "Why do you go out when you know that Umar dislikes that and is jealous?" She said, "Then what prevents him from forbidding me?" They said, "What prevents him is the saying of the Messenger of Allah (peace and blessings of Allah be upon him): 'Do not prevent the female servants of Allah from the mosques of Allah.'"