ʿUthman did not join the Badr battle because he was married to one of the daughters of Allah's Apostle and she was ill. So, the Prophet ﷺ said to him. "You will get a reward and a share (from the war booty) similar to the reward and the share of one who has taken part in the Badr battle."  

عَنْ بَدْرٍ فَإِنَّهُ كَانَتْ تَحْتَهُ بِنْتُ رَسُولِ اللَّهِ ﷺ وَكَانَتْ مَرِيضَةً فَقَالَ لَهُ النَّبِيُّ ﷺ إِنَّ لَكَ أَجْرَ رَجُلٍ مِمَّنْ شَهِدَ بَدْرًا وَسَهْمَهُ