When Islam became clear and spread in Medinah, the Companions of the Prophet started to immigrate to the city. He said, “The choice of Yathrib as the city to immigrate to was not only the result of the circumstances of the call, but it was a revelation from Allah (Glorified is He). Authentic hadiths verify this point. In one such hadith, the Prophet (peace be upon him) said to the Muslims in Mecca, explaining a dream he had, < Your place for immigration has been shown to me. I have seen salty land, planted with date-palms and situated between two mountains which are made up of black stones> [related by Al-Bukhari].
The Companions understood that the Prophet (peace be upon him) mentioned this dream to them as a form of permission from him for them to immigrate. This is why Aisha (may Allah be pleased with her) said, when the Prophet (peace be upon him) told them about his dream, “So they (the Companions) who wanted to emigrate, immigrated to Medinah after the Prophet (peace be upon him) mentioned this. And some of those who had immigrated to Abyssinia also travelled to Medinah” [related by Al-Bukhari].
Some of the first to immigrate to Medinah included: Bilal ibn Rabah, Saad ibn Abi Waqqas, Ammar ibn Yaseer, and Umar ibn Al-Khattab. Al-Biraa ibn Azib said, “The first to come to us were Mus’ab ibn Umair and the son of Um Maktoom. They used to recite Quran to the people. Bilal, Saad and Ammar ibn Yaseer arrived at Medinah, and then Umar ibn Al-Khattab and twenty other Companions of the Prophet. Then the Prophet (peace be upon him) arrived. I had never seen the people of Medinah so happy as they were with the arrival of the Prophet” [related by Al-Bukhari].
There is no doubt that the difficulties and persection were some of the reasons why the Muslims emigrated from Mecca. Similarly, a safe place for spreading the call, giving a suitable environment in which positive efforts could be exerted, was another reason for the immigration. This was clear from the reports about the second pledge of Al-Aqabah, which clarified that Quraysh denying the Prophet’s prophethood was the reason the Muslims left Mecca. Every believer fled with his religion to Allah and His Messenger, in fear of his belief being affected. And Quraysh used to persecute those from Mecca who followed the Prophet (peace be upon him) to make them leave their religion, and push them out of their country. Therefore, the Muslims had the choice of being tempted to leave their religion, being tortured by Quraysh, or escaping from their city in order to flee from their persecution [adapted from The Blessed Garden].
Quraysh employed many means to try to stop the Muslims from immigrating to Yathrib. This resulted in Quraysh causing many problems for the immigrants: threatening them, capturing their wives and children, taking their money and any other possible trick in order for those who had immigrated to return to Mecca. But all of this did not stop the wave of immigration, because the immigrants were completely willing to leave all worldly matters and its pleasures in order to flee with their religion. There are many heroic and brave stories that indicate this. For example, Um Salamah (may Allah be pleased with her) related the story of her immigration with her first husband, and how Quraysh pulled her and her child from her husband, and then her child from her. The persecution continued for nearly a year before they allowed her to take her son again and to join her husband. The story reflects the depth of her faith and how she suffered for her belief. It also reflects one of the faces of nobility that the Arab society before Islam was known for, as Uthman ibn Talhah accompanied Um Salamah and her child, treating them well, generously and politely. He did not return to Mecca until she reached Yathrib and he was sure she was safe.
As for Suhaib Al-Romy, one of the nobles of Quraysh prevented him from immigrating, saying that he was poor when he came to Mecca. They told him, “Your money increased when you were with us, and reached the great amount it reached. But then you want to leave with your money?! That, by Allah, will never happen.” When Suhaib offered to give money in order to let him free, they agreed to let him go. When the Prophet (peace be upon him) heard about this, he said, <Suhaib has profited>, and then he recited Allah’s saying, {And among the people there are some who give up everything, desiring the good pleasure of Allah. Allah is Most Kind with His slaves} [Surah Al-Baqarah: 207] [adapted from The Blessed Garden].