It is narrated from Hazrat Abu Hurairah (may Allah be pleased with him) that the Holy Prophet (peace and blessings be upon him) said: If a person were to know what punishment there is for passing in front of his praying brother, then it would be better for him to stand there for a hundred years than to pass in front of him in a single moment.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 8837
Hadith Gradingحکم دارالسلام:إسناده ضعيف، وعبيد الله بن عبدالله مجهول، وعبيد الله بن عبدالرحمن ليس بذاك القوي، وفي الاسناد قلب