Hazrat ‘Umar (radhiyallahu ‘anhu) thereafter went to the Muhaajireen (radhiyallahu ‘anhum) and exclaimed in joy, “Congratulate me over my nikaah!” They all congratulated him and enquired as to whom he had married. He replied, “The daughter of Hazrat ‘Ali (radhiyallahu ‘anhu).” He then explained, “Verily Rasulullah (sallallahu ‘alaihi wasallam) said, ‘Every relationship between people will be severed on the day of Qiyaamah besides the relationship which people had with me or because of me (besides the relationship which people had with me through family ties and besides the relationship they had with me through following my example in piety and taqwa).’ I had married my daughter to Nabi (sallallahu ‘alaihi wasallam) and so I also wished to marry a descendant of the Ahl-e-Bayt, the family of Rasulullah (sallallahu ‘alaihi wasallam).” (Isaabah 8/465, Radd-ul-Muhtaar 2/198)

Note: Hazrat Umar (radhiyallahu ‘anhu) wished to acquire the special relationship of Rasulullah (sallallahu ‘alaihi wasallam) through being part of his mubaarak family, just as he had acquired the relationship of Rasulullah (sallallahu ‘alaihi wasallam) through following his mubaarak example in piety and taqwa.