It is recorded in books of history and hadith that after the formation of this blessed union between Sayyidina ‘Umar al Faruq and Sayyidina ‘Ali’s radiya Llahu ‘anhuma daughter, the latter’s sons would frequently visit their sister at the former’s home. There existed no reservations or ill-feelings. The author of Kanz al ‘Ummal documents such an incident with reference to Tarikh Ibn ‘Asakir. His words follow:
عن ابن الحنفية قال دخل عمر بن الخطاب و أنا عند أختي أم كلثوم بنت علي فضمني قال ألطفيه يا أم كلثوم
Ibn al Hanafiyyah recalls, “‘Umar ibn al Khattab entered while I was with my sister Umm Kulthum bint ‘Ali. He embraced me and said (to her), ‘Pamper him, O Umm Kulthum.’”
The muhaddithin have reported yet another incident which clarifies whether a person may look at the hair of his sister or daughter. Ibn Abi Shaibah notes down:
عن أبي البختري عن أبي صالح أن الحسن و الحسين كانا يدخلان على أختهما أم كلثوم و هي تمشط
From Abu al Bakhtari―from Abu Salih:
Hassan and Hussain would enter upon their sister Umm Kulthum while she was combing her hair.
This incident relates to Sayyidina ‘Ali radiya Llahu ‘anhu himself. Both Shia and Sunni have recorded this incident. We have quoted it in the past when proving the nikah of Umm Kulthum from Shia books, with reference to Ibn Abi al Hadid. We reproduce it here to highlight the amiable family relationship they enjoyed. ‘Allamah al Sarakhsi writes in al Siyar al Kabir and it appears in Kanz al ‘Ummal with reference to al Dinawari’s al Mujalasah:
عن مالك بن أوس بن الحدثان قال قدم بريد ملك الروم على عمر بن الخطاب فاستقرضت امرأة عمر بن الخطاب دينارا فاشترت به عطرا فجعلته في قوارير و بعثت به مع البريد إلى امرأة ملك الروم فلما أتاها فرغتهن و ملأتهن جواهر و قالت اذهب إلى امرأة عمر بن الخطاب فلما أتاها فرغتهن على البساط فدخل عمر بن الخطاب فقال ما هذا فأخبرته فأخذ عمر الجواهر فباعه و دفع إلى امرأته دينارا و جعل ما بقي من ذلك في بيت مال المسلمين
Malik ibn Aws ibn al Hadathan reports:
The envoy of the Roman King came to ‘Umar ibn al Khattab. His wife borrowed a gold coin and purchased with it perfume and filled it in bottles and sent them with the envoy to the queen of the Roman King. When she received the gift, she poured out the contents of the bottles and filled them with pearls and issued orders, “Take this to ‘Umar ibn al Khattab’s wife.”
When the gift came, she poured the pearls out onto the bed. Just then ‘Umar ibn al Khattab came in and asked, “What is this?”
She told him the whole story. So ‘Umar took the pearls and sold them. He then gave his wife one gold coin and had the rest deposited into the Muslim treasury.”
Ibn Abi al Hadid Shia adds a little more detail to the incident. Have a look at his words:
وجه عمر إلى ملك الروم بريدا فاشترت أم كلثوم امرأة عمر طيبا بدنانير و جعلته في قارورتين و أهدتهما إلى امرأة ملك الروم فرجع البريد إليها و معه ملأ القارورتين جواهر فدخل عليهما عمر و قد صبت الجواهر في حجرها فقال من أين لك هذا فأخبرته فقبض عليه و قال هذا للمسلمين قالت كيف و هو عوض هديتي قال بيني و بينك أبوك فقال علي عليه السلام لك منه بقيمة دينارك و الباقي للمسلمين جملة لإن بريد المسلمين حمله
‘Umar sent an envoy to the Roman King. Meanwhile, Umm Kulthum his wife, purchased perfume for few gold coins and placed it in two long necked bottles and sent them as a gift for the wife of the Roman king. The envoy returned to her with two bottles filled with pearls. ‘Umar entered upon them after she had poured the pearls in her lap.
He asked, “Where did you get this from?”
She informed him of the incident.
‘Umar took it and said, “This belongs to the Muslims.”
“How?” she asked, “It is in lieu of my gift.”
He said, “Your father will decide this matter between us.”
‘Ali radiya Llahu `anhu said, “You will receive pearls equal to the value of money you spent, and the rest is for the Muslims, since their envoy brought it.”
After reviewing these points, one will learn that:
All these indicate to the beautiful, amiable, and friendly relationship they shared. This brings the discussion of Umm Kulthum’s nikah to an end.
 Kanz al ‘Ummal, vol. 7 pg. 88, first edition, Dakkan.
 Musannaf Ibn Abi Shaybah, vol. 4 pg. 336, book on marriage, chapter on what they said regarding a man looking at his sister’s or daughter’s hair, new edition, Dakkan.
 Sharh al Siyar al Kabir, vol. 3 pg. 74, Hyderabad Dakkan print; Kanz al ‘Ummal, vol. 6 pg. 356, Hadith: 5640, first edition, Dakkan.
 Sharh Nahj al Balaghah, vol. 4 pg. 575 – 576, Beirut print, 1375/1956 edition.