Yahya bin Abd al-Rahman bin Hatib (may Allah have mercy on him) narrates from his father that Sayyiduna Umar (may Allah be pleased with him) gave judgement between two men concerning a man whose father was not known, and Sayyiduna Umar (may Allah be pleased with him) said: Follow whichever of them you wish.
This chain is sahih (authentic) and mawsul (connected).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الدعوى والبينات / 21262