Sayyidna Jareer ibn Abdullah, Radi-Allahu anhu, once sent his servant for buying a horse. The servant made a deal for three hundred dirhams and brought the seller with him so he could be paid. Sayyidna Jareer ibn Abdullah, Radi-Allahu anhu, looked at the horse and realized that the seller had undervalued it. "Would you sell it for four hundred?" he asked. The seller agreed. "How about five hundred?" he continued his unusual "bargaining" and finally bought the horse for eight hundred dirhams. He was later asked why he did so. "The seller was not aware of the true value of this horse, " he explained. "I have simply given him a fair price because I had promised to Prophet Muhammad, Sall-Allahu alayhi wa sallam, to always be sincere and well-wisher for every Muslim."
(6:59) He has the keys to the realm that lies beyond the reach of human perception; none knows them but He. And He knows what is on the land and in the sea; there is not a leaf which falls that He does not know about and there is not a grain in the darkness of the earth or anything green or dry which has not been recorded in a Clear Book.