In The Name of Allaah, The Most Merciful, The Bestower of Mercy.
Allaah [The Most High] says that Shu’aib [alayhis-salaam] said to his people:
وَيَـٰقَوۡمِ أَوۡفُواْ ٱلۡمِڪۡيَالَ وَٱلۡمِيزَانَ بِٱلۡقِسۡطِۖ وَلَا تَبۡخَسُواْ ٱلنَّاسَ أَشۡيَآءَهُمۡ وَلَا تَعۡثَوۡاْ فِى ٱلۡأَرۡضِ مُفۡسِدِينَ
[وَيَـٰقَوۡمِ أَوۡفُواْ ٱلۡمِڪۡيَالَ وَٱلۡمِيزَانَ بِٱلۡقِسۡطِۖ – And O my people! Give full measure and weight in justice] – Meaning: The (same) justice (or fairness) you would be pleased to be treated with (by others)]. [وَلَا تَبۡخَسُواْ ٱلنَّاسَ أَشۡيَآءَهُمۡ – and reduce not the things that are due to the people] – Meaning: Do not reduce what (is due to the people of merchandise or commodities), and thus you steal them due to giving lesser in measurement and weight. [وَلَا تَعۡثَوۡاْ فِى ٱلۡأَرۡضِ مُفۡسِدِينَ- and do not commit mischief in the land, causing corruption]- Meaning: Because indeed persistence in disobedience (to Allaah) corrupts the religious affairs, the (sound) creed and the worldly affairs, and destroys the crops and cattle.
[Source: Tayseer Al-kareem Ar-Rahmaan Fee Tafseer Kalaam al-Mannaan’ by Imaam As-Sadi (rahimahullaah). slightly paraphrased]