Khadija, the princess of Arabia, and Muhammad Mustafa were married in A.D. 595. Fifteen years later, Muhammad was chosen by Allah to be His messenger. As God's messenger, his duty was to promulgate Islam in the world. From that moment, every thing changed for Khadija. She made her entire fortune an endowment for Islam. That endowment could not have come at a more opportune time for Islam. Khadija told her husband that all her vast wealth was his, and he could spend it just as he wished.
Khadija's generosity had a glowing spontaneity.
Muhammad Mustafa "invested" Khadija's wealth in Islam. There has never been a better "investment" in the entire history of mankind. This "investment" was a guarantee that Islam's march would not be halted or even be retarded because of any lack of material means and support. It was an investment that, to this day, is paying enormous "dividends", and will pay "dividends" for every generation of the Muslims, to the end of time itself.
But material wealth was not the only investment that Khadija made in Islam. She also invested her time, talent, energy, spirit and heart in Islam - an investment otherwise known as commitment. She knew her spouse's dreams and hopes, and she shared them all with him.
Khadija's intent in supporting Islam was so transparent that Allah Ta'ala was pleased to call her wealth His Own in the following verse of Quran Majid:
And He found thee in need, and made thee independent. (Chapter 93; verse 8)
"The holy Prophet inherited no wealth and was poor. The true, pure, and sincere love of Khadija not only raised him above want, but made him independent of worldly needs in his later life, enabling him to devote his whole time to the service of Allah." (A. Yusuf Ali)
Allah Ta'ala made His slave, Muhammad, rich with the wealth of Khadija.
Khadija and the Two Migrations to Abyssinia
Two groups of Muslims left Makka in the years 615 and 616 to escape persecution by the Quraysh and they sought sanctuary in Abyssinia. The total number of men and women in both groups was about one hundred.
With a few exceptions like Uthman and Zubayr, the rest of the refugees in these two groups were too poor to bear the expenses of travel to Abyssinia. Who equipped their caravans and paid their expenses so they were able to travel? The historians have not answered this question. But it is most probable that Khadija equipped the caravans and financed the emigration of the Muslims from Makka to Abyssinia. In Makka, she alone had the resources with which to underwrite emigration of Muslims on such a scale.