Hadith 2631
It is narrated from Sayyiduna Abu Bakr Siddiq (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) was asked: "Which deed is the best?" He (peace and blessings be upon him) replied: "Raising the voice in Talbiyah and offering sacrifice." Imam Abu Bakr (may Allah have mercy on him) says that "al-'ajj" means raising the voice in Talbiyah, and "ath-thajj" means slaughtering the camel and shedding its blood.