Establishing the Sutrah
Just before a person prayers, he or she, must establish a Sutrah.
This is a any Tall Object About The Height Of A Saddle which we should place Just Beyond the Place of Prostration and try not to let any thing pass between us and the sutrah.
Place anything (about the height of a saddle) just beyond the place of prostration. Things that can be used are: a wall, bed, tall pillow, tall purse, tall stick, tree, etc. Anything that breaks the path between the person praying and someone who "may" need to pass in front. It's best to pray facing a wall, bed, or any other type of tall object, so that there will be no need for someone to pass directly in front. Do not mind anyone who passes beyond the sutrah.
The Prophet (SAW) said, "Do not pray except towards a sutrah, and
do not let anyone pass in front of you, but if someone continues
(to try to pass) then fight him, for he has a companion (i.e. a
Shaitan) with him." (Sahih - Al-Bukhari and Ahmad)
"When he (SAW) prayed (in an open space where there was nothing to
use as a sutrah) he would plant a spear in the ground in front of
him and pray towards it with the people behind him." (Sahih -
Al-Bukhari and Muslim)
The Prophet (SAW) said, "When one of you places in front of him
something such as the stick on the end of a saddle, he should pray
and not mind anyone who passes beyond it." (Sahih - Muslim and Abu
Dawood)
Learn how to pray ( perform salah (arabic word for prayer) , namaz (urdu word for for prayer)