Narrated Al-Mughira bin Shu`ba: The Prophet used to pray so much that his feet used to become edematous or swollen, and when he was asked as to why he prays so much, he would say, "Shall I not be a thankful slave (to Allah)?"
Hadith ReferenceSahih Bukhari / The Book of Ar-Riqaq (Softening of The Hearts) / Hadith: 6471
Hadith Gradingمحدثین:أحاديث صحيح البخاريّ كلّها صحيحة