And those who keep their trusts and covenants.meaning, if they are given a trust they do not deceit and when they make a covenant they do not break it.These are the characteristics of the believers which are opposite of the characteristics of the hypocrites.This is like what is reported in the authentic Hadith,ايَةُ الْمُنَافِقِ ثَلَثٌ إِذَا حَدَّثَ كَذَبَ وَإِذَا وَعَدَ أَخْلَفَ وَإِذَا اوْتُمِنَ خَانThe signs of the hypocrites are three.- When he speaks he lies,- when he promises he breaks his promise,- and when he is given a trust he behaves treacherously (with it).In another narration it states,إِذَا حَدَّثَ كَذَبَ وَإِذَا عَاهَدَ غَدَرَ وَإِذَا خَاصَمَ فَجَر- When he speaks he lies,- when he makes a covenant he breaks it,- and when he argues he is abusive.Concerning Allah's statement,وَالَّذِينَ هُم بِشَهَادَاتِهِمْ قَايِمُونَ