Mentioning some of the jurisprudential consequences of not placing a barrier in front of the one who prays.

The Shaykh : I said: Either it leads to a cause for the invalidation of the prayer, and this is its evidence, or it exposes the prayer to a reduction in its reward and virtue. There are two hadiths regarding this:
The first is his saying (peace and blessings be upon him): , and in the other hadith: :
Therefore, we must revive this recommended practice (sunnah) which the Prophet (peace and blessings be upon him) commanded, and he adhered to it throughout his life, and his Companions followed him in this, as you heard in the hadith of Anas: that when the people entered the mosque and the mu'adhdhin began the adhan, the Companions of the Prophet (peace and blessings be upon him) would rush to the pillars, meaning the columns, and pray behind them, meaning they would use them as a barrier. So, in whichever mosque you are, you should approach the wall or the pillars, which are the columns, and use them as a barrier so that Satan does not pass in front of you. Let no one say that we are praying and it is likely that no one will pass by. First, this contradicts the witnessed reality. Then, there is a type of Allah's creation that is not seen, as He the Exalted said regarding Iblis: So let no one say that no one passes in front of me while I am praying, for Satan, whom a person does not see, may pass in front of him. It is established in *Sahih Muslim* in a story mentioned there, the summary of which is: that Satan intended to cut off the prayer of the Prophet (peace and blessings be upon him), and he came upon him with a flame of fire. The Prophet (peace and blessings be upon him) was able to overpower him with the strength and special status that Allah Mighty and Majestic gave him, and he nearly strangled him until he felt the coldness of his saliva on his fingers (peace and blessings be upon him). He said: لقد هممتُ أن أربطه بسارية من سواري هذا المسجد حتى يصبح يلعب به صبيان المدينة -وأطفال المدينة أو كما قال عليه الصلاة والسلام- لولا دعوة أخي سليمان: رب هب لي ملكًا لا ينبغي لأحد من بعدي I intended to tie him to one of the pillars of this mosque until the boys of the city would play with him -and the children of the city, or as he (peace and blessings be upon him) said- if not for the supplication of my brother Sulayman: "My Lord, grant me a kingdom that will not belong to anyone after me.". If Satan intended to cut off the prayer of the Messenger (peace be upon him), then we are even more in need of protection. Protection from him is following the Messenger (peace and blessings be upon him) in word and deed.
And he (peace and blessings be upon him) used to pray in his mosque, and there would be a space between the place of his prostration and the wall equal to the passage of a sheep. This is the recommended practice (sunnah) when the one who prays faces the barrier. When he prostrates, there should be a space between the place of his prostration and the barrier, whether it is a wall, a column, or something similar, equal to the passage of a sheep, one or two shibr. By doing so, we revive this recommended practice (sunnah) and obey his command (peace and blessings be upon him): . This is the first matter that I saw it as my duty to remind my brothers of.