What are the rulings concerning the sutrah (barrier) for one praying, in terms of its width; and does the prayer get interrupted if something passes outside of it, if the sutrah is a pillar much narrower than the worshipper; and what is the ruling on a sutrah that is open from the bottom, like a chair or a table?

It is Sunnah (definition) for the worshipper, whether leading the prayer or praying alone, to place a sutrah (barrier) in front of him during prayer, based on the Prophet's (peace and blessings be upon him) saying: "When one of you prays, let him pray towards a sutrah and draw near to it." The wisdom behind the sutrah is to prevent the worshipper's gaze from wandering beyond it, to help him concentrate, and to prevent passersby from committing the sin of passing in front of him.

The Sunnah is for the sutrah to be upright and at least two-thirds of a cubit in height. There is no limit to its width or thickness. Anything that stands upright, such as a wall, a tree, or a pillar, or anything that is planted, such as a stick, a spear, or an arrow, is sufficient. The Prophet (peace and blessings be upon him) used to use a short spear ('anzah) and a spear as his sutrah. It is preferable for the sutrah to be wide if available. If the worshipper uses a chair, a table, or similar hollow objects as a sutrah, it is sufficient.