Muhammad bin Abdullah al-Thaqafi relates that in Basrah there was a man named Nafi' Abu Abdullah. He came to Sayyiduna Umar (may Allah be pleased with him) and said: In Basrah there is land which is neither kharaj land nor does it cause harm to the Muslims, and Sayyiduna Abu Musa (may Allah be pleased with him) (the governor) has written to you so that you may know of it. Sayyiduna Umar (may Allah be pleased with him) wrote to Sayyiduna Abu Musa (may Allah be pleased with him): If it is land that causes no harm to the Muslims and is not kharaj land, then grant it to him as an estate.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب إحياء الموات / 11793