When the Holy Prophet, peace and blessings of Allah be upon him, passed away, Hazrat Umar, may Allah be pleased with him, came forth, sword in hand, and said: ‘I shall kill anyone who says that the Holy Prophet, peace and blessings of Allah be upon him, has died’. In these circumstances, Hazrat Abu Bakr Siddiqra spoke with remarkable bravery and courage; he stood up and delivered an address. He recited the following verse of the Holy Quran:
مَا مُحَمَّدٌ اِلَّا رَسُوۡلٌ ۚ قَدۡ خَلَتۡ مِنۡ قَبۡلِهِ الرُّسُلُ
Meaning, Muhammad, peace and blessings of Allah be upon him, is only a Messenger of Allah Almighty, and all the Prophets that have gone by before him, have all passed away. It was on this that emotion subsided. After this, the Arab nomads turned apostate. Hazrat Ayeshah, may Allah be pleased with her, describes these delicate times and says: ‘When the Messenger, peace and blessings of Allah be upon him, passed away, there were a number of false claimants to prophethood who came forth. Some abandoned the Prayer and the circumstances changed completely. In this state of affairs and in this calamity, my father became the Caliph who succeeded the Holy Prophet, peace and blessings of Allah be upon him. My father was faced with such griefs that if they had descended upon the mountains, they would have crumbled.’
Now reflect, it is not the work of any ordinary man to stand firm with courage and resolve when overwhelmed with mountains of grief. This steadfastness requires a love for truth and sincerity (sidq) and it was this Truthful One (Siddiq) known as Abu Bakrra who demonstrated this quality. It was impossible for any other person to confront these perils. All the companions were present at the time, but no one said that he was more deserving of the office of Caliphate. For they could see that a fire was ablaze around them. Who could have been willing to cast themselves into this fire? In these circumstances, Hazrat Umar, may Allah be pleased with him, extended his hand and swore his allegiance to Hazrat Abu Bakrra, after which everyone, one after the other, swore their allegiance as well. It was the sincerity (sidq) of Hazrat Abu Bakrra that suppressed the uprising and put an end to the rebels. Musaylamah had an army of 100,000 and he taught a religious ideology that promoted freedom from divine law. When people would see his teachings of non-conformity, they would enter his religion in large numbers. However, God Almighty clearly demonstrated that He was with Hazrat Abu Bakrra and eased all of his travails.
(Malfuzat [English], Vol. 2, pp. 92-93)