Sayyiduna Ibn Umar (may Allah be pleased with them both) narrates that the Messenger of Allah (peace and blessings be upon him) said: "You must certainly pray with a sutrah, and do not let anyone pass in front of you. Then if he refuses (to stop), then fight him, for indeed there is a companion (Satan) with him."
The meaning of the Prophet (peace be upon him) is that with the one who passes in front of a person praying, there is a devil; it does not mean that the person passing is himself a devil, although the word "devil" is also used for disobedient humans. Allah Almighty says, « وَكَذَٰلِكَجَعَلْنَالِكُلِّنَبِيٍّعَدُوًّاشَيَاطِينَالْإِنسِوَالْجِنِّيُوحِيبَعْضُهُمْإِلَىٰبَعْضٍزُخْرُفَالْقَوْلِغُرُورً »[ سورة الأنعام : 112 ] "In this way, We have made for every prophet enemies—devils from among mankind and jinn—who inspire one another with decorative speech in delusion."