Al-Bara' (May Allah be pleased with him) reported:
The Messenger of Allah (ﷺ) said, "Two Muslims will not meet and shake hands without having their sins forgiven (by Allah ) before they depart."[Abu Dawud]. (DE)
App reference (DE): Book 6, Hadith 43 (DE)
Arabic/English book reference (DE): Book 6, Hadith 887 (DE)