وَعَنْ أَبِي هُرَيْرَةَ رضى الله عنه
قَالَ: قَالَ رَسُولُ اَللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ -«إِذَا صَلَّى أَحَدُكُمْ فَلْيَجْعَلْ تِلْقَاءَ وَجْهِهِ شَيْئًا، فَإِنْ لَمْ يَجِدْ فَلْيَنْصِبْ عَصًا، فَإِنْ لَمْ يَكُنْ فَلْيَخُطَّ خَطًّا، ثُمَّ لَا يَضُرُّهُ مَنْ مَرَّ بَيْنَ يَدَيْهِ»
The Messenger of Allah (sallallahu alayhi wa sallam) said: “When one of you prays, he should put something in front of him, and if he cannot find something he should set up a stick; but if he has no stick with him he should draw a line, then what passes in front of him will not harm him.”.
Bulugh al-Maram 280, Book 2, The Book of Prayer, Hadith 101. 1 min read