Ammar bin Abi Ammar says that once he passed by Hazrat Abdur Rahman bin Samurah (may Allah be pleased with him) who was at the canal of Umm Abdullah and, along with boys and slaves, was letting the water flow. Ammar said to him, "O Abu Saeed, today is Friday." He replied, "The Prophet (peace and blessings be upon him) used to say: On the day when there is heavy rain, you should pray in your tents."
Hadith Referenceمسند احمد / أول مسند البصريين / 20620
Hadith Gradingحکم دارالسلام:صحيح لغيره، وهذا إسناد حسن