Sayyiduna Asim (may Allah have mercy on him) narrated the like of this from Sayyiduna Ali (may Allah be pleased with him), and added: "When they exceed one hundred and twenty, the dues revert to their beginning, and when the camels become many, then on every fifty a hiqqah." And this is dearer to Sufyan (may Allah have mercy on him) than the view of the people of the Hijaz.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الزكاة / 7261