Praise be to Allah, and may Allah’s peace and blessings be upon the Messenger of Allah, his family and his companions.   Wa alaikum assalam wa rahmatullahi wa barakatuh.   As to what follows:   In response to your question, we say:   A woman’s going out for prayer whether it is a compulsory or optional prayer is from the practices of the pious predecessors. It has been transmitted in the Sahihayn from the hadith of ‘Abdullah ibn ‘Umar (peace be upon him) that the Prophet (peace be upon him) said, “Do not prevent Allah’s female slaves from going to the mosques” [al-Bukhari (900) and Muslim(442)], that is “Allah’s female slaves” refers to women. The word imaa (female slaves) is opposite to ‘abeed (male slaves), it is the plural of amah, and the amah is a female servant who worships Allah the Exalted. The hadith states that women should not be prevented from going to the mosques, and this covers all types of going to the mosque, regardless of whether the woman is going to perform a compulsory prayer or an optional prayer. Rather, even if she goes to the mosque to seek knowledge, she should not be prevented from attending the circles of knowledge in the mosques according to some scholars. The prohibition stated in the hadith covers all prohibitions, regardless of whether the prayer is compulsory or optional, and from this is the Taraweh prayer, and a woman must not be prohibited from going to the mosque to perform this prayer if she wishes. Men and women from the pious predecessors used to attend the Taraweh prayer as is stated in history books, and transmitted from the actions of the pious predecessors. Moreover the hadith of ibn ‘Umar (may Allah be pleased with him) that I mentioned states that ‘Umar’s wife used to attend the prayers in the mosque, and it was said to her, “Why do you come to the mosque for prayer yet ‘Umar is jealousy and does not want you to come?” She said, “Why does he do not prevent me from coming,”  that is she used his silence as proof for permission to go to the mosque. ‘Umar said to her, “I did not prevent you from going to the mosque because the Messenger of Allah (peace be upon him) said, “Do not prevent the Allah’s female slaves from going to the mosques.”