Matam, Azadari

Sunni scholar said Shia Mourned Fatima and Muhsin

Tathbit Dala'il al-Nubuwwa, vol. 2, pp. 594–595
Qadi Abd al-Jabbar names a number of Shia figures of his own time, including Abu Abdullah Muhammad ibn al-Nu'man. He then says that these people, living in places including Egypt, Ramla, Tyre, Acre, Asqalan, Damascus, Baghdad and Jabal al-Basmaq, professed Shiism and love for the Messenger of Allah and his Ahl al-Bayt. They wept for Fatima and for her son Muhsin, whom they claimed Umar had killed, and they held recitations and lamentations concerning this.
وأبي عبد الله محمد بن النعمان، فهؤلاء بمصر وبالرملة وبصور، وبعكا وبعسقلان وبدمشق وببغداد وبجبل البسماق، وكل هؤلاء بهذه النواحي يدعون التشيع ومحبة رسول الله صلى الله عليه وسلم وأهل بيته، فيبكون على فاطمة وعلى ابنها المحسن الذي زعموا أن عمر قتله، ويقيمون المنشدين والمناحات في ذلك.