In A.D. 622, the Holy Prophet decided that the Muslims should migrate from Mecca to Madina. The Muslims were required to proceed to Madina in batches.
Abu Salmah Abdullah bin Ashhal was the first Muslim to migrate from Mecca to Madina. He was followed by Bilal and Ammar Yasir. Thereafter Umar migrated from Mecca. While most of the other Muslims left Mecca in secret, Umar publicly declared that he was proceeding to Madina. He even challenged the Quraish that if any one of them had the courage to stop him from going to Madina, he was welcome to try his strength with hin. No Quraish of Mecca could have the courage to prevent the migration of Umar, and no one accepted the challenge to measure strength with him.
According to Ibn Asakir, Ali commented on the migration of Umar in the following terms:
I never knew any one migrate unless secretly except Umar, for he, when he resolved on migration, girt on his sword and slung over his bow and grasped in his hand its arrows, and went to the Ka'bah where in its quadrangle were the chiefs of the Quraish, and he went round about it seven times, then prayed two raka'ts at the station of Abraham, and went to each, one by one, in their circle and said, "May the face be foul of such as desire that his mother be bereaved of him and his child be left an orphan and his wife a widow, and if there be such a one, let him meet me behind this valley, but no one followed him.
In Sahih Bukhari it is stated that some twenty Muslims accompanied Umar on the occasion of his migration from Mecca. His companions included Zaid bin Khattab the brother of Umar; Said bin Zaid, the nephew of Umar and Khunais bin Hudhaifah the son-in-law of Umar (the husband of Hafsa). Other persons who accompanied Umar included: Amr b Suraqah; Abdullah b Suraqah; Waqid b Abdullah Tamimi; Khaula b Abi Khaula; Malik b Abi Khallla; Ayas b Bukair; Aqil b Bukair; Amir b Bukair and Khalid b Bukair.
Ayyash b Abu Rabiah al- Makhzumi and Hisham b Al-Aas b Wail al-Sahmi also decided to migrate with Umar. They made an appointment to meet at the thorn tree of Adat of Banu Ghifar about ten miles from Mecca. It was decided that if any one of them failed to turn up at the appointed place by sunrise on the day of departure fixed before hand it would be construed that he was not coming and had been held back by force.
Umar with his companions and Ayyash arrived at the appointed meeting place according to schedule. Hisham did not turn up and was held back by the Quraish.
The party arrived at Quba on the outskirts of Madina and there they stayed with Banu Amr bin Auf.
One day Abu Jahl and al-Harith rode to Quba and contacted Ayyash who was their cousin. They told Ayyash that his mother had vowed that she would not comb her hair, nor take shelter from the sun until she saw Ayyash.
Umar told Ayyash that this was nothing but an attempt to seduce him from his religion. Umar added that if the lice disturbed his mother she would of her own accord comb her hair, and if the heat of Mecca oppressed her, she would herself take shelter.
But Ayyash felt inclined to go. He said:
"I may go for a short while. I will clear my mother of her vow. I have also some money to recover from the people in Mecca which I would like to get."
"I am one of the richest of the Quraish and if you do not go with them, you may have one half of my money."
Ayyash, however, persisted in his wish to go to Mecca once .
Thereupon Umar said:
"If you must go, then take this camel of mine. She is well bred and easy to ride. Don't dismount, and if at any stage you suspect them of treachery, you may well escape on this camel. Then Ayyash left for Mecca on the camel of Umar. After they had proceeded some distance, Jahl said to Ayyash:
"I find my beast hard to ride. Will you not mount me behind you ?"
Ayyash agreed, and when they made their camels kneel to make the change over, Abu Jahl and al-Harith fell on Ayyash and bound him securely. They brought him to Mecca bound and said:
"O men of Mecca deal with your fools as we have dealt with this fool of ours".
When the Holy Prophet came to know how Hisham had been held back and how Ayyash had been abducted, he said:
"Who will bring me Ayyash and Hisham?"
Al-Walid b al-Mughira volunteered to undertake the mission. Al-Walid rode to Mecca and there he came to know that Hisham and Ayyash were kept in custody in a house which had no roof. One night al-Walid climbed the wall and contacted the prisoners who were in fetters. Al-Walid cut the fetters with the strokes of his sword. Then al-Walid led Ayyash and Hisham to Medina.
Having arrived in the neighbourhood of Madina, Umar and his party chose to stay at Quba, a suburb of Madina. Umar had about twenty persons with him including his brother Zaid, Khunais bin Hudaifah his son-in-law; Waqid bin Abdullah al Tamimi, and Ayyash. At Quba Umar and his party were the guests of Rifa'a bin Abdul Mundhir of Banu Amr. Umar and his party were accommodated in a few independent houses where they were lodged comfortably. There was already a mosque at Quba and here Umar prayed at the appointed hours.
At Quba all the Muslims waited eagerly for the Holy Prophet to come. Parties of men would go out for some distance on the route to Mecca and there wait for the Prophet to come. Several days passed away and the Holy Prophet did not come. Umar felt uneasy and he thought of going to Mecca to ascertain why the Holy Prophet was late in coming.
Then one noon the Holy Prophet accompanied by Abu Bakr arrived at Quba. As they arrived the people crowded round them. As the people had not seen the Holy Prophet before, it was difficult for them to know as to who out of the two was the Holy Prophet. Seeing this predicament of the people, Abu Bakr stood up and shielded the Holy Prophet with his mantle. Umar arrived at the spot and rushed to meet the Holy Prophet. The Holy Prophet embraced Umar and the chiefs of Quba who had come to we come him.
The Holy Prophet stayed at Quba for a few days and led the prayers in the mosque. Then the Holy Prophet proceeded to Madina. Umar followed in the train of the Holy Prophet. At Madina the Holy Prophet and the emigrants from Mecca were given a royal reception. The maidens of Madina mounted the roof tops of their houses and sang:
The full-moon has arisen on us
The world of Madina was quite different from the world of Mecca. At Mecca the Muslims weere a persecuted people; at Madina they were the masters of their destiny. The life at Madina was a complete break with the past. The days of trials, tribulations and torture were over; they were now set on the path of fulfilment. They were now to build a new commonwealth and a new ideal society.
At Madina, the Holy Prophet had a mosque built. The Holy Prophet himself participated in the construction of the mosque Umar used to go every day from Quba to Madina to participate in the construction of the mosque. As the Muslims laboured they chanted:
"There is no life but the life of the next world,
To rehabilitate the emigrants from Mecca in the society of Madina the Holy Prophet established a fraternity among the Muslims of Mecca and those of Madina whereunder each migrant was paired with an Ansar of the corresponding status. The brotherhood thus established was unique in the annals of mankind. So strong and cordial were these bonds that these even surpassed the relationship of blood. In this roll of brotherhood, Umar was paired with Itban bin Malik of Banu Al-Khazraj.
The climate of Mecca was dry, but the climate of Madina was damp. The change adversely affected the health of the emigrants. On arrival at Madina most of the emigrants fell sick, Umar was blessed with robust constitution, and he was one of the few emigrants who did not suffer due to the change in climate.
In Mecca Umar was a trader. He had brought ample amount with him from Mecca. In Madina he started business afresh. He had his store at Quba and from there goods were supplied to the market at Madina. No details about the business of Umar are available. Umar was a shrewd businessman, and we have reasons to hold that his business flourished at Madina as it did at Mecca. After attending to business, Umar spent his spare time in the company of the Holy Prophet. The Holy Prophet consulted Abu Bakr and Umar on all important matters. When Abu Bakr and Umar held different views on a matter, the Holy Prophet took both the views into consideration before taking his decision. When Abu Bakr and Umar agreed on a point that view was invariably accepted by the Holy Prophet.
We have it on the authority of Abdur Rahman-bin-Ghanam that the Holy Prophet said to Abu Bakr and Umar that "if you two are agreed upon a counsel, I would not oppose you". (Suyuti 'History of the Caliphs').