It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said on the day of Eid al-Adha: "Of all that the son of Adam does on this day, there is no deed better than shedding blood (in sacrifice), except that a severed tie of kinship be joined."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 10902