Busr ibn Sa’eed said that Zayd ibn Khalid Juhanni sent someone to Abu Juhaym to learn of the rules applying to one who walks ahead of those who are engaged in salah. Abu Juhaym said that Allah’s Messenger (SAW) said, “If one who passes in front of another who is praying knew the punishment against what he does then he would prefer to stand still for forty years rather than pass in front of him. Abu an-Nadr, a narrator said, “I do not know if he said forty days or months or years.’