What did Abu Bakr As-Siddique initially refuse to do when 'Umar presented Hafsa to him for marriage out of respect for the Prophet Muhammad (saw)?
 Narrated `Abdullah bin `Umar:                     `Umar bin Al-Khattab said, "When Hafsa bint `Umar became a widow after the death of (her husband) Khunais bin Hudhafa As-Sahmi who had been one of the companions of the Prophet, and he died at Medina. I went to `Uthman bin `Affan and presented Hafsa (for marriage) to him. He said, "I will think it over.' I waited for a few days, then he met me and said, 'It seems that it is not possible for me to marry at present.' " `Umar further said, "I met Abu Bakr As-Siddique and said to him, 'If you wish, I will marry my daughter Hafsa to you." Abu Bakr kept quiet and did not say anything to me in reply. I became more angry with him than with `Uthman. I waited for a few days and then Allah's Apostle asked for her hand, and I gave her in marriage to him. Afterwards I met Abu Bakr who said, 'Perhaps you became angry with me when you presented Hafsa to me and I did not give you a reply?' I said, 'Yes.' Abu Bakr said, 'Nothing stopped me to respond to your offer except that I knew that Allah's Apostle had mentioned her, and I never wanted to let out the secret of Allah's Apostle. And if Allah's Apostle had refused her, I would have accepted her.' "