Bulugh al-Maram
Book 7, Hadith 69
Arabic hadith text
وَلِمُسْلِمٍ:" وَكَذَلِكَ اَلْمِيزَانُ "1 .1 - مسلم ( 1593 ) ( 94 ).
Translation
Muslim has
"and so is (that which is sold by) weight."