It is narrated from Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him) that he (peace and blessings be upon him) said: "I have made sacred the area between the two mountains of Madinah, just as Ibrahim made Makkah sacred."
(b) He said: Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him) would find a bird in the hands of one of us, take it, free it from his hand and then let it go.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9964