It is narrated from Sayyidah Aishah (may Allah be pleased with her) that the Prophet (peace and blessings be upon him) said: "Whoever cultivates land that belongs to no one, he is more entitled to it." Urwah said: Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) gave judgement accordingly during his caliphate.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب إحياء الموات / 11812