Abu al-Aswad al-Ansari narrates from his father, and he from his grandfather (may Allah be pleased with him), and Baqiyyah named him: I was the seventh of seven with the Messenger of Allah (peace and blessings be upon him). The Prophet (peace and blessings be upon him) said: "The sacrifices most beloved to Allah are those whose price is highest and which are the fattest."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الضحايا / 19082