Nafi' (may Allah have mercy on him) said that Ubaydullah bin Umar (may Allah be pleased with him) was killed at the Battle of Siffin, and Mu'awiyah (may Allah be pleased with him) bought his sword and sent it to Abdullah bin Umar (may Allah be pleased with them both). Juwayriyah (may Allah have mercy on him) said: I said to Nafi' (may Allah have mercy on him): Was it the sword of Umar (may Allah be pleased with him)? He said: Yes. I said: How much was its ornamentation? He said: They obtained forty dirhams from its scabbard tip.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الزكاة / 7575