Yahya related to me from Malik from Ismail from Ibn Abi Hakim
that he had heard that the Messenger of Allah, may Allah bless him and
grant him peace, heard a woman praying at night. He said, "Who is
that?" and someone said to him,"It is al-Hawla bint Tuwayt, she does
not sleep in the night." The Messenger of Allah, may Allah bless him
and grant him peace, disapproved of that and his disapproval showed in
his face. Then he said, "Allah, the Blessed and Exalted, does not
become weary, but you become weary. Take on whatever is within your
capability."
Muwatta Malik Book 7, Hadith 4