Mukh-khah (rahimahallah), one of the sisters of Bishr Haafi (rahimahullah), would constantly refer to Imaam Ahmad bin Hambal (rahimahullah) in order to ask him questions pertaining to piety and asceticism. Such was the depth of understanding behind her questions that Imaam Ahmad (rahimahullah) would express amazement over her outstanding intelligence.
Mukh-khah (rahimahallah) once went to Imaam Ahmad (rahimahullah) and posed the following question, “O Imaam! Tell me! Is the groan of a sick person in distress and discomfort not actually a complaint against the decree of Allah Ta‘ala?”
Imaam Ahmad (rahimahullah) replied, “I have hope that the groan of the sick person is actually a complaint addressed to Allah Ta‘ala, not against Allah Ta‘ala.” After hearing the answer of Imaam Ahmad (rahimahullah), Mukh-khah (rahimahallah) exited and left.
Imaam Ahmad (rahimahullah) then turned to his son, ‘Abdullah (rahimahullah), and exclaimed, “O my son! I have never heard a question as intelligent as this before! Follow this woman and see which home she enters so that you may identify her.” When ‘Abdullah (rahimahullah) followed her and successfully identified her, he returned to his father, Imaam Ahmad (rahimahullah) and informed that the woman was none other than the sister of Bishr Haafi (rahimahullah). When he heard this, Imaam Ahmad (rahimahullah) exclaimed, “It was impossible for her to be anyone but the sister of Bishr Haafi (rahimahullah)!”
(Reference: Sifatus Safwah vol. 1 pg. 577)