Musnad Ahmad 1:73

'Abd al-Razzaq narrated to us, he said: Ma'mar informed us, from al-Zuhri, from Salim, from Ibn 'Umar, from 'Umar, who said: Hafsa bint 'Umar became a widow from Khunays ibn Hudhafa—or Hudhayfa, 'Abd al-Razzaq was uncertain—and he was one of the companions of the Prophet, may Allah bless him and grant him peace, who had witnessed Badr, and he died in Medina. He said: So I met 'Uthman ibn 'Affan and offered Hafsa to him. I said: "If you wish, I will marry Hafsa to you." He said: "I will look into that." I waited for some nights, then he met me and said: "I do not wish to marry on this day of mine." 'Umar said: So I met Abu Bakr and said: "If you wish, I will marry Hafsa bint 'Umar to you." He did not return anything to me, and I was more vexed with him than I was with 'Uthman. I waited for some nights, then the Messenger of Allah, may Allah bless him and grant him peace, proposed to her, so I married her to him. Then Abu Bakr met me and said: "Perhaps you were vexed with me when you offered Hafsa to me and I did not return anything to you?" I said: "Yes." He said: "Nothing prevented me from returning anything to you when you offered her to me except that I had heard the Messenger of Allah, may Allah bless him and grant him peace, mention her, and I was not going to disclose the secret of the Messenger of Allah, may Allah bless him and grant him peace. And had he left her, I would have married her."