Source for "The believer feels at ease with people and they feel at ease with him"?

Today in the Friday sermon I've heard the following expression which is apparently a part of a hadith on the authority of Jabir () saying: > "The believer feels at ease with people and they feel at ease with him. ..." > > "... المؤمن يألف ويؤلف" I'd like to know the possible sources for this statement and whether it is indead a hadith or a saying of a sahabi etc.? If you could provide similar (sourced) statements in other ahadith that would be great?