Some of the children of Sa'd narrate from Sayyiduna Sa'd (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever you catch cutting any of the trees of the sanctuary of Madinah, his belongings are yours. Its trees are not to be lopped or cut." The narrator said: Sayyiduna Sa'd (may Allah be pleased with him) saw some slaves cutting trees, so he took their belongings. They went to their masters and told them that Sayyiduna Sa'd (may Allah be pleased with him) had done such and such. They came and said: O Abu Ishaq, your slaves or your freedmen have taken the belongings of our slaves! Sayyiduna Sa'd (may Allah be pleased with him) said: Rather, I took them. I heard the Messenger of Allah (peace and blessings be upon him) say: "Whoever you catch cutting the trees of the sanctuary, his belongings are yours." But ask me for whatever you wish from my own wealth.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9974