According to the terms of the treaty of Hudaibiya the Arab tribes had the option to be allied with the Quraish or the Muslims. As a consequence the Banu Bakr joined the Quraish, and the Khuza'ah joined the Muslims.
In disregard of the treaty, Banu Bakr attacked the Khuza'ah and even when the Khuza'ah sought the sanctuary of the Ka'aba, many persons of the Khuza'ah were chased and put to death.
The Khuza'ah wanted the Muslims to come to their aid in accordance with the terms of the treaty. The Holy Prophet gave an ultimatum to the Quraish making three alternative demands, i.e.
In a fit of arrogance the Quraish replied that they would neither pay blood money, nor terminate their alliance with Banu Bakr, and that they were prepared to consider the Hudaibiya pact as having been abrogated.
The Muslims in general and Umar in particular were happy that the Hudaibiya pact of which they were critical had been abrogated by the Quraish themselves.
The Quraish soon realized that they had imprudently abrogated the treaty. Abu Sufiyan the leader of the Quraish visited Madina to arrive at some amicable settlement. He wanted his daughter who was a wife of the Holy Prophet to plead for him with the Prophet but she refused. Abu Sufiyan waited on Abu Bakr and Ali but they did not listen to him. He sought the help of Umar, and Umar made him understand that there could no longer be any reconciliation with the Quraish unless they accepted Islam. The peace efforts having proved futile, Abu Sufiyan returned to Mecca.
After Abu Sufiyan had left Madina, the Holy Prophet ordered preparations to be made for a foray. As Umar came to see his daughter Hafsa, he saw that she was packing some goods. He enquired whether Holy Prophet had ordered her to get things packed up, and she said that he had. Later the Holy Prophet took Umar into confidence and told him that he was leading an expedition to Mecca, and that he was also to accompany him.
The Holy Prophet mustered a force over ten thousand strong and marched to Mecca. Having reached the neighborhood of Mecca the Muslim army encamped at Marr al-Zahran
The Holy Prophet sent Hadrat Abbas to Mecca on a diplomatic mission. Hadrat Abbas met Abu Sufiyan and advised him that the best course for him and the Quraish was to place themselves at the mercy of the Holy Prophet. Abu Sufiyan agreed to wait on ~he Holy Prophet to get terms.
Umar saw Abbas and Abu Sufiyan proceeding to the camp of the Holy Prophet. Hadrat Umar strode forward Hurriedly, and addressing the Holy Prophet said. "Permit me to behead Abu Sufiyan the enemy of Islam." The Holy Prophet said, "Umar, wait for a while and see."
At the Muslim camp, Abu Sufiyan was converted to Islam. That was the end of the Quraish opposition.
The following day the Muslim army marched triumphantly into Mecca. One of the contingents was lead by Umar.
The triumphant entry of the Muslims in Mecca marked the vindication of the truth of Islam. The city which ten years ago had treated the Muslims cruelly, and had driven them to seek refuge with strangers, now lay at the feet of the Muslims.
In the hour of triumph the Holy Prophet forgot every evil suffered, and forgave every injury that had been inflicted on him. He granted general amnesty to the people of Mecca.
The Holy Prophet along with his companions visited the Ka'aba. The idols were broken, and one by one the stone gods were destroyed. Thereupon the Holy Prophet recited the verse from the Holy Qumran:
"Say the Truth is come and falsehood gone; Verily falsehood is ever vanishing."
The people assembled at the Ka'aba, and the Holy Prophet delivered the following address:
"There is no god but Allah. He has no associate. He has made good His promise that He held to his bondman and helped him and defeated all the confederates. Bear in mind that every claim of privilege, whether that of blood or property is abolished except that of the custody of the Ka'aba and of supplying water to the pilgrims. Bear in mind that for any one who is slain the blood money is a hundred camels. People of Quraish, surely God has abolished from you all pride of the time of ignorance and all pride in your ancestry, because all men are descended from Adam, and Adam was made of clay." Then the Holy Prophet turning to the people said:
"O ye Quraish, what do you think of the treatment that I should accord you.?"
And they said, "Mercy, O Prophet of Allah. We expect nothing but good from you."
Thereupon the Holy Prophet declared:
"I speak to you in the same words as Joseph spoke to his brothers. This day there is no reproof against you; Go your way, for you are free."
The announcement was received with greatest joy and applause. Then accompanied by Umar the Holy Prophet ascended the brow of the Safa to initiate the people to the vow of allegiance to Islam. The people came in large numbers to be converted to Islam. After the oath-taking ceremony of men was over, the Holy Prophet directed Umar to take the oath of allegiance from women on his behalf. All the Quraish ladies in Mecca took the oath of allegiance to Allah, the Holy Prophet and Islam at the hands Umar.
After the fall of Mecca, the neighboring tribes of Howazin and Sagef had to choose between Islam and war against Muslims. They chose the war path, and the two tribes along with their allies mustered in considerable strength at Autas to the west of Mecca. The coalition was led by Malik bin Auf a fiery commander of considerable skill.
When the Holy Prophet came to know of the hostile intention of the tribes, he decided to take action against them. On a cold day in January 630 A.D. the Muslim forces set out from Mecca. The army consisted of 12,000 persons fully armed. Out of these 10,000 were from Madina who had attacked Mecca and 2,000 were the newly converted Muslims from Mecca.
As on the way to Autas the Muslim army passed through the valley of Hunain, some eleven miles north east of Mecca, a rain of arrows fell on the Muslims let loose by a group of archers of the hostile tribes who lay hid in the mountain pass. Taken unawares the advance guard of the Muslim army fled in panic. There was considerable confusion, and camels, horses and men ran into one another to seek cover.
The Holy Prophet stood firm. There were only nine companions around him including Umar. All the rest had fled. Under the instructions of the Holy Prophet, Abbas shouted at the top of his voice, "O Muslims, come to the Prophet of Allah".
The call was heard by the Muslim soldiers, and they gathered round the Holy Prophet. When the Muslims had gathered in sufficient number, the Holy Prophet ordered a charge against the enemy. In the hand to hand fight that followed, the tribes were routed and they fled to Autas.
The Holy Prophet posted a contingent to guard the Hunain pass, and led the main Muslim army to Autas. In the confrontation at Autas, the tribes could not withstand the Muslim onslaught. Finding the resistance useless the tribes broke the camp and retired to Taif.
From Autas the Muslim forces set out for Taif. The tribes shut themselves in the fort and refused to come out in the open. The Muslims employed catapults to throw stones in the town, but this did not lead to any tangible results. The Muslims tried the tostado device "hereunder a group of soldiers shielded by a cover of cowhide advanced to set fire to the gate. The enemy threw red hot scraps of iron on the tostado which made it ineffective.
The siege dragged on for two weeks, and still there was no sign of the fall of the fort. The Holy Prophet held a council of war. The companions including Umar advised that the siege might be raised and that God would Himself make arrangements for the fall of the fort.
The advice was accepted, and in February 630 the siege of Taif was raised, and the Muslim army returned to Mecca. A few days later, Malik bin Auf came to Mecca of his own accord and became a Muslim. Thus God Himself arranged for the surrender of Taif to Islam.
In A.D. 630 the Holy Prophet decided to lead an expedition to Tabuk on the Syrian border. In order to finance the expedition the Holy Prophet invited contributions and donations from his followers.
Umar had then considerable wealth with him, and he thought that was the occasion for him to excel Abu Bakr in the matter of donation in the way of God.
Umar went home and he returned loaded with considerable wealth. When the Holy Prophet asked him how much he had left for himself and his family, he said that he had given one half of his wealth in the way of Allah, and had left one half for himself and his dependents. The Holy Prophet was much pleased at the contribution, and he thanked Umar profusely.
Then Abu Bakr came carrying his contribution, and the Holy Prophet put to him the same question as to how much wealth he had left for himself and his family. Abu Bakr said, "I have brought all that I had. I have left Allah and His Prophet for myself and my family."
This episode has formed the theme of one of the poems of Allama Iqbal. The last verse of the poem reads:
"For the moth the lamp, and for the nightingale the flower,
For Siddiq, God and His Prophet alone suffice."
The call to arms was given at a very inconvenient time. The weather was burning hot. Crops were ripe and ready for harvesting. The journey to the Syrian border was long and arduous. Many persons preferred to stay back. In spite of obstacles and difficulties, an army of thirty thousand persons was raised.
The Muslim army reached Tabuk after a weary march.
There was no Byzantine force to meet the Muslims. On coming to know of the advance of the Muslim army, the Byzantines had withdrawn their army well within Syria. The Muslims achieved their object without firing a shot.
The Byzantines who had at one time threatened to invade Arabia were no longer in the mood to measure swords with the Muslims. The tribes in the region which were under the paramountcy of the Byzantines transferred their allegiance to the Muslims.
At Tabuk, the Holy Prophet delivered a classical address which has passed into history. He said:
"Verily the most veracious discourse is the Book of Allah.