It is narrated from Tariq bin Shihab who said: "We set out for Hajj, and one of us, whose name was Arbad, hunted a deer and wounded its back. We came to Umar (may Allah be pleased with him), and Arbad asked him about it. Umar (may Allah be pleased with him) said: 'Arbad, you yourself decide (what compensation you should give).' He said: 'O Commander of the Faithful! You are more knowledgeable and better than me.' Umar (may Allah be pleased with him) said to him: 'I order you to decide in this matter; I did not order you to describe my qualities.' So Arbad said: 'In my opinion, its compensation is a goat that is fit for grazing.' Umar (may Allah be pleased with him) said (confirming): 'That is its compensation.'"
Hadith Referenceمسند الإمام الشافعي / كتاب الحج / 887
Hadith Takhrijاسناده صحیح اخرجه البيهقي: 182/5 ، 185 - وعبدالرزاق (8221) وابن أبي شيبة (15616)۔