Muwatta Malik Book 8, Hadith 39
Yahya related to me from Malik from Hisham ibn Urwa from his
father that a woman asked him for a decision, saying, "Waist-wrappers
are painful to me. Can I pray in a shift and head-covering?" He
replied, "Yes, if the shift is long."
Yahya related to me from Malik from a reliable source from Bukayr ibn Abdullah ibn al-Ashajj from Busr ibn Said that when Ubaydullah ibn al-Aswad al-Khawlani was in the room of Maimuna, the wife of the Prophet, may Allah bless him and grant him peace, she used to pray in a shift and head-covering, without a waist-wrapper.
Yahya related to me from Malik from Da'ud ibn al-Husayn from al- Araj from Abu Hurayra that the Messenger of Allah, may Allah bless him and grant him peace, joined dhuhr and asr on his journey to Tabuk.