The best lines for the men are those in the front, the worst lines are the last and the best lines for the women are at the rear and the worst are at the front.

[Q]: Here there are some mosques where the women pray under the mosque, in a basement level or above the mosque on another floor. And we women sometimes pray in these mosques, following the imām from where we cannot see the imām, nor the followers, and sometimes there is a large empty space in the area where the men pray. Is such praying of ours acceptable, especially when we cannot see the imām, nor any of the followers? Sometimes when we enter the mosque we do not know which rakaʿah (unit of prayer) he is in. So is it permissible in this situation to follow the takbīr by the voice only? Is it permissible for us to follow the imām while we are on a lower or upper floor, knowing that there is sometimes space remaining in the mosque itself?

[A]: The answer consists of two parts:

1. Prayer in such circumstances is acceptable wherever the women pray in the mosque, whether that is in an upper or lower floor. As long as they hear the takbīrāt of the imām in the standing position, in the bowing position and in the prostration.
2. There is no reason for the women to have to perform their prayer like this, except when the area of the men is too crowded and there is no room for the women’s prayer behind them. In this case, it is allowed for them to pray on an upper or lower floor. But when this mosque, where the imām, prays with the men behind him, has a lot of space left in it, then it is not permissible for the women to go to up to an upper floor or to go down to a lower floor where they will not see the movement of the imām, nor the movements of the followers. There are two reasons for this:

• The Prophet (ṣallallāhu ʿalayhi wa-sallam) said: “The best lines for the men are those in the front, the worst lines are the last and the best lines for the women are at the rear and the worst are at the front.” Here he means the ground upon which the Prophet (ṣallallāhu ʿalayhi wa-sallam) and his Companions prayed, whereas the women were not on an upper or lower floor.
• Another reason for this is that the voice could sometimes be soft and at other times completely unheard so that the prayer of the followers on the upper or lower floor who cannot see the people behind the imām praying in vulnerable to becoming void.

So to summarise this answer, the prayer in an upper or lower level is acceptable, but it is not allowed to designate such a place for prayer when there is clearly enough space in the men’s muṣallá (designated place of prayer) that the women can pray in the back behind them.