Ammar passed by Abdul-Rahman bin Samura while he was at the canal of Umm Abdullah, channeling the water along with his servants and freed slaves.Ammar said to him, "Abu Saeed, the Friday prayer."Abdul-Rahman bin Samura replied, "The Messenger of Allah ﷺ used to say, 'When it is a day of heavy rain, let each of you pray at his lodging.'"
حدثنا عبد الله قال وجدت في كتاب أبي بخط يده وأكبر علمي أني قد سمعته منه حدثنا علي بن عبد الله حدثنا ناصح بن العلاء مولى بني هاشم
أنه مر على عبد الرحمن بن سمرة وهو على نهر أم عبد الله يسيل الماء مع غلمته ومواليه فقال له عمار يا أبا سعيد الجمعة فقال له عبد الرحمن بن سمرة إن رسول الله ﷺ كان يقول إذا كان يوم مطر وابل فليصل أحدكم في رحله
Its chain of transmission is hasan, due to Nasih bin Ala. Ibn Madini and Abu Dawud deemed him trustworthy, and Ahmad approved of him, while Nasai and Bukhari deemed him daif. Hakim graded his hadith as sahih in 1/292, but Dhahabi disagreed with him. However, the hadith has corroborating narrations, and this has come up many times before. See 17456 and its cross-references, and 20136 and its cross-references.