Sayyiduna Abu Sa'id (may Allah be pleased with him) says: Two men disputed over a date palm. The Prophet (peace and blessings be upon him) cut one of its fronds and measured with it, and found it to be five (cubits), so he made that its surrounding boundary.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب إحياء الموات / 11864
It is narrated from Sayyiduna Ubadah bin al-Samit (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) gave judgement concerning a man who had one, two or three date palms among (other people's) palms, and they disagreed about their rights. He (peace and blessings be upon him) judged: "For each of their palms there is as much land as the reach of its fronds."
(b) In the Marasil of Abu Dawud it is reported from Urwah bin al-Zubayr (may Allah have mercy on him) that the Messenger of Allah (peace and blessings be upon him) judged "the surrounding boundary of date palms to be the length of their fronds."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب إحياء الموات / 11866