Sayyiduna Abd al-Rahman bin Awf (may Allah be pleased with him) said: Umayyah asked me while I was walking with him: "O Abd al-Ilah, who is the man among you marked with an ostrich feather on his chest?" I said: "That is Sayyiduna Hamzah bin Abd al-Muttalib (may Allah be pleased with him)." He said: "He is the one who did all those things to us."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب صلاة الخوف / 6114