Surah Ad-Dukhan,(44) Verse 7:
رَبِّ السَّمَاوَاتِ وَالْأَرْضِ وَمَا بَيْنَهُمَا إِن كُنتُم مُّوقِنِينَ
The Lord of the heavens and the earth and all between them, if ye (but) have an assured faith.
(English – Yusuf Ali)
If person has surah (barrier) in front of him
Then it is permissible to pass beyond the surah but not between the praying person and surah
(a)It was narrated from “Abdur-Rahman bin Abu Sa’eed that his father said: “The Messenger of Allah (ﷺ) said: “When anyone of you performs prayer, let him pray facing towards a Sutrah, and let him get close to it, and not let anyone pass in front of him. If someone comes and wants to pass in front of him, let him fight him, for he is a Shaitan (satan).’
Ibn Majah : Vol. 1, Book 5, Hadith 954
Warning to him who tries to pass across the (i;e in between place of prostration and standing) praying person :
Busr b Sa’id reported that Zaid b Khalid al-Juhani sent him to Abu Juhaim in order to ask him what he had heard from the Messenger of Allah (ﷺ) with regard to the passer in front of the worshipper. Abu Juhaim reported that the Messenger of Allah (ﷺ) said:
If anyone who passes in front of a man who is praying knew the responsibility he incurs, he would stand still forty (years) rather than to pass in front of him Abu Nadr said: I do not know whether he said forty days or months or years.
Sahih Muslim 507
From the above Ahadeeth from the keen observation it is clear that passing Infront means “between place of prostration and standing” but there is no harm if someone passes beyond those place
if someone wants to pass in front of a person who is praying, one of the following scenarios must apply:
1 – If he passes in front of the one who is praying, i.e., in the area between the spot where he puts his forehead when he prostrates and where he stands, this is haraam, and indeed it is a major sin as the Prophet (peace and blessings of Allaah be upon him) said: “If the one who passes in front of a person who is praying knew what (a burden of sin) he bears, it would be better for him to stand for forty rather than pass in front of him.” Abu’l-Nadar – one of the narrators – said: I do not know whether he said forty days or months or years.
Narrated by al-Bukhaari, 510; Muslim, 507 – from Abu Juhaym (may Allaah be pleased with him).
In this case it makes no different whether the person has a sutrah (object to serve as a screen) or not.
2 – If he passes in the area that is beyond the place where he prostrates. Two scenarios may apply in this case:
(i) If the one who is praying has set up a sutrah (object to serve as a screen). In this case it is permissible to pass beyond the sutrah, because the Prophet (peace and blessings of Allaah be upon him) said: “If any one of you prays, let him face towards something. If he cannot find anything, then let him set up a stick. If he cannot do that, then let him draw a line, then it will not matter if anyone passes in front of him.”
Narrated by Ahmad, 3/15; Ibn Maajah, 3063; Ibn Hibbaan, 2361. Ibn Hajar said in al-Buloogh, 249: The one who said that it is mudtarab (a kind of weak hadeeth) is not right; rather it is hasan.
And it was narrated that Talhah (may Allaah be pleased with him) said: The Messenger of Allaah (peace and blessings of Allaah be upon him) said: “If one of you puts something in front of him that is like the back of a saddle, then let him pray and not worry about anyone who passes beyond that.” Narrated by Muslim, 499.
(ii) If the one who is praying has not set up a sutrah, he has no more than the space in which he prostrates. This is the most correct scholarly opinion. It is permissible for the one who wants to pass in front of him to pass in the space beyond where he prostrates. That is because the prohibition mentioned in the hadeeth applies to passing in front of the one who is praying, and what is beyond the place where he prostrates is not counted as being in front of the one who is praying.
Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him) said, after mentioning the differences of scholarly opinion concerning the distance within which the worshipper should stop anyone from passing in front of him:
The most correct opinion is that it is the distance between his feet and the place where he prostrates. That is because the one who is praying has no right to anything more than what he needs for his prayer. So he does not have the right to prevent the people from (using space) that he does not need.
Reference : Al-Sharh al-Mumti’, 3/340.
ALLAH knows best