A sutrah (Arabic: سترة lit., "screen, cover") is an object used by a person performing salat as a barrier between himself and one passing in front of him. The person praying should be positioned at less than or equal to three forearms' length away from the Sutrah. The Sutrah’s height must be no less than one forearm's length (i.e. the height of the rear end of a camel's saddle), whereas its width has no stipulated size. The Sutrah is compulsory for anyone performing salat (unless a Sutrah cannot be found after searching).
While it is apparent that it might appear like the performer is praying to the object in front of him/her, it's not absolutely necessary while praying. It can be substituted by facing a wall or simply blocking the way of a passer with a hand. It is also forbidden for someone to pass in-between a person praying and his Sutrah, or to pass closer than 3 forearms' length to the person who has no Sutrah in front of him (because 3 forearms' length is the furthest distance which one can stay away from a Sutrah). However, a person is allowed to pass between the rows of a congregational salat.
Hadiths related to Sutrah
Sahl ibn Abu Hathmah narrated: إذا صلى أحدكم إلى سترة فليدن منها لا يقطع الشيطان عليه صلاته The Prophet said: When one of you prays facing a sutrah he should keep close to it, and not let the devil interrupt his prayer.
The Messenger of Allah said: لا تصل إلا إلى سترة، ولا تدع أحداً يمر بين يديك، فإن أبى فلتقاتله؛ فإن معه القرين Pray facing a sutrah, and let no one cross in front of you while praying. If he insists, then prevent him by force because he is accompanied by shaitan.
Rulings on Sutrah
According to the Sunni Hanafi Madhab, one's prayer will not be nullified if someone crosses one without sutrah. According to the Hanbali Scholar Shaykh Bin Baz, if someone prays without a sutrah, the prayer would still be valid unless a donkey, a black dog or an adult woman walks in front of them.
- Bukhari, Book 2, Volume 15, Hadith 89, 90: The Two Festivals (Eids)
- Bukhari, Book 1, Volume 8, Hadith 373, 422: Prayers
- Bukhari, Book 1, Volume 4, Hadith 187: Ablutions
- Sahih Muslim, Book 4, Hadith 1011: The Book of Prayers
- Muslim, Book 4, Hadith 1008, 1009: The Book of Prayers
- Bukhari, Book 1, Volume 9, Hadith 485: Virtues of the Prayer Hall (Sutra of the Musalla)
- Bukhari, Book 1, Volume 9, Hadith 488, 489: Virtues of the Prayer Hall (Sutra of the Musalla)
- Muslim, Book 4, Hadith 1023: The Book of Prayers
- Sunan Abu Dawud :: Book 2 : Hadith 695
- Sahih Ibn Khuzaimah, Chapter: Salat, Hadith No. 793
- Al Mabsut Vol. 1, page 191
- Majmoo’ Fataawa Ibn Baaz (24/21, 22)