"I heard the Messenger of Allah say: 'There is no one on earth, or under the sky, who speaks more truthfully than Abu Dharr.'"  

سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ مَا أَقَلَّتِ الْغَبْرَاءُ وَلاَ أَظَلَّتِ الْخَضْرَاءُ مِنْ رَجُلٍ أَصْدَقَ لَهْجَةً مِنْ أَبِي ذَرٍّ