Umm Sulaym bint Milhan reported,

The Prophet ﷺ used to come to her and take his afternoon nap at her home. She would spread out a leather mat for him on which he would nap. He used to perspire heavily, so she would gather his sweat and put it into perfume and flasks.She said, and he used to pray on a small prayer mat.

Azami 2586

Sahih

عن أم سليم

أن النبي ﷺ كان يأتيها فيقيل عندها، فتبسط له نطعا فيقيل عندها، وكان كثير العرق، فتجمع عرقه، فتجعله في الطيب والقوارير، قالت: وكان يصلي على الخمرة.

الأعظمي 2586صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Prayer
Chapter
What one may pray in
Section
Prayer on a small mat and a reed mat
Numbering
Jami al-Kamil 2586 (2nd edition)
Azami 2586