Abu Hurairah (May Allah be pleased with him) reported:
The Messenger of Allah (ﷺ) said, "Shall I not tell you something by which Allah effaces the sins and elevates the ranks (in Jannah)." The Companions said: "Yes (please tell us), O Messenger of Allah." He said, "Performing the Wudu' properly in spite of difficult circumstances, walking with more paces to the mosque, and waiting for the next Salat (prayer) after a observing Salat; and that is Ar-Ribat, and that is Ar-Ribat."[Muslim].
App reference: Book 9, Hadith 69
Arabic/English book reference: Book 9, Hadith 1059