Muwatta Malik 887

These are the words of a Companion, not of the Prophet ﷺ. The chain is graded on its own terms.

وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ نَافِعٍ، أَنَّ عَبْدَ اللَّهِ بْنَ عُمَرَ، قَالَ مَنْ نَذَرَ بَدَنَةً فَإِنَّهُ يُقَلِّدُهَا نَعْلَيْنِ وَيُشْعِرُهَا ثُمَّ يَنْحَرُهَا عِنْدَ الْبَيْتِ أَوْ بِمِنًى يَوْمَ النَّحْرِ لَيْسَ لَهَا مَحِلٌّ دُونَ ذَلِكَ وَمَنْ نَذَرَ جَزُورًا مِنَ الإِبِلِ أَوِ الْبَقَرِ فَلْيَنْحَرْهَا حَيْثُ شَاءَ ‏.‏

Yahya related to me from Malik from Nafi that Abdullah ibn Umar said, "Someone who vows to sacrifice a camel or a cow to Allah should garland it with two sandals about its neck, and brand it by causing blood to flow from its side. He should then sacrifice it either at the House or at Mina on the day of sacrifice. There are no other correct places apart from those. However, someone who vows to slaughter a camel or a cow simply as a sacrifice can sacrifice it wherever he wishes