بُلُوغُ الْمَرَامِ
Bulugh al-Maram 234
The Book of Prayer
وَعَنْ أَبِي سَعِيدٍ اَلْخُدْرِيِّ - رضى الله عنه - قَالَ : قَالَ رَسُولُ اَللَّهِ - صلى الله عليه وسلم -{ إِذَا صَلَّى أَحَدُكُمْ إِلَى شَيْءٍ يَسْتُرُهُ مِنْ اَلنَّاسِ , فَأَرَادَ أَحَدٌ أَنْ يَجْتَازَ بَيْنَ يَدَيْهِ فَلْيَدْفَعْهُ , فَإِنْ أَبَى فَلْيُقَاتِلْهُ , فَإِنَّمَا هُوَ شَيْطَانٌ } مُتَّفَقٌ عَلَيْهِ . [1]
Narrated Abu Sa'id al-Khudri (RA): Allah's Messenger (ﷺ) said: "If one of you prays towards an object separating him from the people and someone tries to pass (between him and the object) in front of him, let him turn him away but if he refuses he should fight him for he is a devil." [Agreed upon].
Sunnah.com reference: Book 2, Hadith 101