Hadith 8:2916
Abu Bakr narrated to us, he said: Yahya ibn Sa'id narrated to us, from Ubayd Allah, from Nafi', who said: Ibn Umar used to collect his sandals from the Sunnah, and he would hang them around the neck of his sacrificial animal (badana). When they became worn out, he would buy new sandals and hang them around its neck.
حدثنا أبو بكر قال نا يحيى بن سعيد عن عبيد الله عن نافع قال كان بن عمر يجمع نعله من السنة فيقلدها بدنته فإذا عجزت اشترى نعالا جددا فقلدها