مُسْنَدُ أَحْمَدَ
Musnad Ahmad 1452
Musnad Abu Ishaq Sa'd bin Abi Waqqas
It was narrated from Abu Salamah bin Abdur-Rahman, from Sa"d bin Abi Waqqas that The Prophet (ﷺ) said concerning wiping over the khuffain (leather slippers): “There is nothing wrong with it.”
Musnad Ahmad 1452Sahih (Darussalam)]