The saying of Allah, Exalted be His praise: "Do not consume one another's wealth unjustly among yourselves, except that it be trade by mutual consent among you." [Surah al-Nisa: 29]
And He said: "And Allah has made trade lawful and has forbidden usury (riba)." [Surah al-Baqarah: 275]
Mujahid (may Allah have mercy on him) says concerning the saying of Allah Almighty: "Eat of the good things with which We have provided you" [Surah al-Baqarah: 57], that what is meant is trade.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 10394