Sayyiduna Abu Hurayrah (may Allah be pleased with him) said: Banu Khuza'ah killed a man of Banu Layth in retaliation on the day of the Conquest of Makkah. When he (peace and blessings be upon him) learned of it, he (peace and blessings be upon him) mounted his riding animal and delivered a sermon: "Allah protected Makkah from the elephants and made His Messenger and the believers its inheritors. Listen! Makkah was not lawful for anyone before, nor will it ever be. Yes, for me it was made lawful for part of a day, and now, at this hour, its sanctity is established and lasting again. No one is to break its thorns, nor uproot its trees, nor pick up anything that has fallen (lost) here, except one who announces it. And whoever has someone of his killed has the choice of the better of two things: he may take blood money or retaliation." A man from the people of Yemen named Abu Shah came and said: Write these things down for me. He (peace and blessings be upon him) said: "Write for Abu Shah." A man of Quraysh said: O Messenger of Allah, at least permit the idhkhir grass, for we use it in our houses and in our graves. So he (peace and blessings be upon him) said: "Very well! You may uproot the idhkhir grass."
And in Sahih al-Bukhari, Abu Nu'aym narrates from Shayban: "Either he pays (the blood money) or he gives retaliation."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنايات / 16039