Answered by Shaykh Faraz Rabbani
I recently attended a function where during prayers the men and women were segregated, but with the men and women standing to the left and right of the imam rather than men in front and women behind them. Some brothers refused to pray in this setting and decided to pray separately because they believed this prayer arrangement invalidates the man’s prayers. Which opinion is correct does praying in this way invalidate the man’s prayer, the women’s prayer, both or neither?
Walaikum assalam wa rahmatullahi wa barakatuh,
I pray this finds you in the best of health and spirits.
The Prophet (Allah bless him and give him peace) instructed that men stand in front and women behind them in prayer. This is the sunna and proper manner of arranging the rows of men and women in prayer, unless there are overwhelming secondary considerations.
If men and women stand in the manner you describe, but there is a clear gap (and, ideally, a barrier) between the rows, this would be valid, but (normally) contrary to the sunna, for the abovementioned reason.
[ Shurunbulali, Maraqi al-Falah; Ibn Abidin, Radd al-Muhtar; Nawawi, al-Majmu` Sharh al-Muhadhdhab ]
And Allah alone gives success.
Faraz Rabbani