Do This and Allaah will Build a House for You in Paradise
by The Albaani Site
The Imaam said, “The Merit of Filling the Gaps in the Rows [for Prayer]:
The Prophet ﷺ said, ‘Whoever fills a gap, Allaah will build a house for him in Paradise and raise him one degree in status thereby.’” [Saheeh]
As-Silsilah as-Saheehah, 4/515.
The Albaani Site 