Amr bin Abdullah al-Ansari (may Allah have mercy on him) asked Sa'id bin al-Musayyib (may Allah have mercy on him) about a sacrificial camel that a woman had made binding upon herself. Sa'id bin al-Musayyib (may Allah have mercy on him) said that the camel is to be taken to the House of Allah and sacrificed there; if she named a place, saying she would sacrifice it at such-and-such a place, then she should do it at that very place. If she does not find a camel, then she should sacrifice a cow; if a cow cannot be found, she should sacrifice ten goats in its place. The narrator said: Then I came to Salim bin Abdullah (may Allah have mercy on him), and he too said what Sa'id bin al-Musayyib (may Allah have mercy on him) had said, except for this difference: if a cow is not found, she should slaughter seven goats in its place. The narrator said: Then I came to Kharijah bin Zayd (may Allah have mercy on him), and he too said what Salim bin Abdullah (may Allah have mercy on him) had said. Then I came to Abdullah bin Muhammad bin Ali bin Abi Talib (may Allah have mercy on him), and he too said what Salim (may Allah have mercy on him) had said.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 10167