Muwatta Malik 1665

وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ أَبِي الزِّنَادِ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏ "‏ لاَ يَمْشِيَنَّ أَحَدُكُمْ فِي نَعْلٍ وَاحِدَةٍ لِيُنْعَلْهُمَا جَمِيعًا أَوْ لِيُحْفِهِمَا جَمِيعًا ‏"‏ ‏.‏

Yahya related to me from Malik from Abu'z-Zinad from al-Araj from Abu Hurayra that the Messenger of Allah, may Allah bless him and grant him peace, said, "Do not wear one sandal. Wear both of them or go with both feet bare

Reference

Muwatta Malik 1665

In-book

Book 48, Hadith 15