This Hadith highlights the desirability on part of the customer of paying in excess of the agreed price. The seller is induced to give more than the agreed (quality/weight/number of goods etc.) against the settled price. This is a step ahead of justice - that is Ihsan, which has very salutary effects on society. On the contrary, if people are in the habit of encroaching up others' rights, it will doubtless create jealousy and enmity, which are ruinous to the society.