Tirmidhi

685. Commentary:
It is understood that not placing a sutrah causes harm to the one praying. That is, there is a decrease in his humility, submissiveness, and reward, or at the very least, the harm of falling short in following the command is evident. And this sutrah should be something at least between one foot to one and a half feet in height.

Benefits and Issues:
➊
When a person is praying in a place where there is a likelihood of people passing in front of him, it is Sunnah to place a sutrah (barrier) in front of him.

➋
What kind of sutrah should it be, and how high should it be? This is determined by this hadith: it should be as high as the rear part of a camel’s saddle. This is approximately one and a quarter to one and a half feet. Accordingly, the sutrah should be at least one and a quarter to one and a half feet high.

➌
This indicates that if someone passes in front of the person praying, his prayer will be affected. Some scholars have interpreted this to mean that it affects the humility and concentration (khushu‘ and khudu‘) in prayer. When there is a sutrah, the attention of the person praying remains confined to a limited space. In Sahih Muslim, the Prophet’s (sallallahu alayhi wa sallam) statement is: “The prayer of one who prays without a sutrah is broken by the passing of a woman, a donkey, and a black dog.” (Sahih Muslim, Salat, Chapter: The extent of what should screen the one who prays, Hadith: 510)
In Sunan Ibn Majah (Hadith: 949), the words “al-mar’ah al-ha’id” (a menstruating woman) are used. By this is meant an adult woman. It is possible that it means if a woman is menstruating and passes in front, the prayer is broken, otherwise not; but the first meaning appears more correct. And Allah knows best.

➍
Shaykh Ahmad Shakir rahimahullah (of Egypt) has considered the hadith in Sunan Abu Dawud (“Nothing breaks the prayer”) (Sunan Abu Dawud, Salat, Chapter: Whoever said nothing breaks the prayer, Hadith: 719) as abrogating all these ahadith. He further said that the narration in (Sunan Daraqutni: 3/367 and Sunan al-Kubra by al-Bayhaqi: 2/278) supports this view. For details, see: (Jami‘ at-Tirmidhi, Salat, Chapter: What has been reported that nothing breaks the prayer except a dog, a donkey, and a woman, Hadith: 338, footnote by Shaykh Ahmad Shakir rahimahullah).

➎
The purpose of the sutrah is that if someone wants to pass, he should pass beyond the sutrah and not between the sutrah and the person praying.