After prophet Mohamed peace be upon him death , almost all the Arabian tribes left Islam some refuse to pray and some refuse to pay zakat. in all ways this period was one of the hardest period on true Muslims. But Abu_Bakr led Muslim through this period, and united Arabian tribes under the flag of Islam.
Realizing that his end was drawing near, #Abu_Bakr felt that he should
nominate his successor so that the issue should not be a cause of
dissension among the Muslims after his death.The general consensus was that #Umar was the fittest person to be
appointed as the Caliph. Usaid bin Hudai said, "After you, O Caliph,
Umar is the most deserving person for the office of the Caliph.
#Abu Bakr said: "I can say from my personal experience that #Umar has
always cooled me down whenever I have lost my temper with any one, just
as whenever he felt me to be too lenient he counseled greater severity.
For this reason I feel certain that with time, Umar will achieve the
moderation that you desire.
Approval of the people. The testament having been drawn up, Abu Bakr supported by his wife Asma walked up to the door and addressed the people who had collected there. He told them that he had appointed Umar as his successor. They said, "We approve". After obtaining the approval of the people in general terms, Abu Bakr lay on the bed, and prayed to God: "O Lord! I have made this testament for the welfare of the community in order to counteract discord among them. What my intentions are, You know full well. I have spared no pains in making the best selection, O God, I entrust the Muslims to Your care. O Allah, keep their ruler on the right path. O God, make my successor the most pious of rulers, and confer peace on the Muslims."
When Abû Bakr Al-Siddîq was on his deathbed he called ‘Umar – Allah be pleased with them – and said:
Fear Allah o ‘Umar, and know that Allah has deeds to be done for Him in the day which He will not accept if done at night, and He has deeds to be done for Him at night which He will not accept if done during the day. He will not accept extra (nâfilah) deeds unless you fulfill the obligatory deeds. The scales of those whose scales will be weighty on the Day of Resurrection will only be weighty because they followed the truth in this life and it was weighty to them. And scales in which the truth will be placed tomorrow truly deserve to be heavy.
And the scales of those whose scales will be light on the Day of Resurrection will only be light because they followed falsehood in this life and it was a light matter to them. And scales in which falsehood will be placed tomorrow truly deserve to be light.
Allah the Exalted has mentioned the people of Paradise and mentioned them in the context of their best deeds, and overlooked their evil deeds, so when I remember them I say to myself: I fear that I will not be included with them. And Allah the Exalted has mentioned the people of Hell and mentioned them in the context of their worst deeds and rejected their best deeds, so when I remember them I say: I hope I won’t be amongst them. Allah’s worshippers should always be in a state of hope and fear, they shouldn’t wish flimsy wishes about Allah and neither should they despair of Allah’s mercy.
If you keep to this advice of mine, no one who is not with you now should be more beloved to you than death – and it is sure to come to you. But if you disregard this advice, no one who is not with you now should be more hated to you than death – and you cannot escape it.
Abû Nu’aym, Hilyah Al-Awliyâ` Vol.1 p18; and Ibn Al-Jawzî, Sifah Al-Safwah.