وَلَا تَأْكُلُوا أَمْوَالَكُمْ بَيْنَكُمْ بِالْبَاطِلِ وَتُدْلُوا بِهَا إِلَى الْحُكَّامِ لِتَأْكُلُوا فَرِيقًا مِنْ أَمْوَالِ النَّاسِ بِالْإِثْمِ وَأَنْتُمْ تَعْلَمُونَ
And do not eat up your property among yourselves for vanities, nor use it as bait for the judges, with intent that ye may eat up wrongfully and knowingly a little of (other) people’s property. Quran 2: 

إِنَّنِي أَنَا اللَّهُ لَا إِلَٰهَ إِلَّا أَنَا فَاعْبُدْنِي وَأَقِمِ الصَّلَاةَ لِذِكْرِي
Verily, I am Allah: There is no god but I: So serve thou Me (only), and establish regular prayer for celebrating My praise. Quran 20: 14