Walking in front of someone while praying

Question:
Is it permissible to walk across in front of someone who is praying Salaat?

Answer:

Praise be to Allah.

It is not permissible to walk across in front of someone who is praying, and it is a great sin, as the Prophet (peace be upon him) said (approximate translation of meaning is):

“If the one crossing in front of a praying person knew what sin is upon him, it would be better for him to wait forty than walk across.” Abu Al-Nadhr (one of the narrators of the hadith) said: I don’t know whether he said forth days, months, or years. (Bukhari)

Imam Al-Bukhari (R) has named the chapter in which he brings the hadith as follows: Chapter on the sin of walking across in front of a praying person.

When the praying person is the leader in the prayer or praying alone, and he has a sutrah( some object like a peice of wood) in front of him, then walking across in between him and his sutrah is not permitted. However, if he is praying without a sutrah, it is not permissible to walk across in between him and his place of prostration. For the followers (in a jamaa’ah prayer), the leader’s sutrah is enough for them. Based on this, it is permissible to walk through in front of a row if need be.

And Allah knows best.

“It was We Who created man, & We know what dark suggestions his soul makes to him: for We are nearer to him than (his) jugular vein. Behold, two (guardian angels) appointed to learn (his doings) learn (& noted them), one sitting on the right & one on the left. Not a word does he utter but there is a sentinel by him, ready (to note it).”

(Al-Qur’an, 50:16-18 (Qaf [The letter Qaf])

Sahih Muslim : Book 32, Number 6221)
Abu Huraira (Radi Allah Anhu) reported Allah’s Messenger (sal-allahu-alleihi-wasallam) as saying: “Verily Allah does not look to your faces and your wealth but He looks to your heart and to your deeds.”