Hadhrat Khadijah RA had aided, assisted and supported the Noble Messenger of Allah ﷺ, her husband, right from the first day of his mission of Nubuwwah.
Because she had helped Nabi ﷺ so much, it was only natural for Khadijah RA to receive her share of the harassment meted to him by none other than those who, not long ago, used to call him as-Sadiq and al-Amin. Khadijah RA did not hesitate to embrace Islam at all, knowing that her husband could not have put forth any false claim.
Yahya ibn `Afeef is quoted as saying that he once came, during the jahiliyya (the period preceding the advent of Islam), to Makkah to be hosted by al-Abbas ibn Abdul-Muttalib, one of the Prophet ﷺ’s uncles.
“When the sun started rising,” says he, “I saw a man who came out of a place not far from us, faced the Ka`ba and started performing his prayers.
He hardly started before being joined by a young boy who stood on his right side, then by a woman who stood behind them. When he bowed down, the young boy and the woman bowed, and when he stood up straight, they, too, did likewise. When he prostrated, they, too, prostrated.” Then he expressed his amazement at that, saying to al-Abbas: “This is quite strange, O Abbas!” “Is it, really?” retorted Abbas. “Do you know who he is?” Abbas asked his guest who answered in the negative. “He is Muhammad ibn Abdullah, my nephew. Do you know who the young boy is?” asked he again. “No, indeed,” answered the guest. “He is Ali son of Abu Talib. Do you know who the woman is?” The answer came again in the negative, to which Abbas said, “She is Khadijah, daughter of Khuwaylid, my nephew’s wife.” This incident is included in the books of both Imam Ahmad and al-Tirmithi, each detailing it in his own Sahih book.
And she bore patiently in the face of persecution to which her revered husband and his small band of believers were exposed at the hands of the polytheists and aristocrats of Quraish, sacrificing her vast wealth to promote Islam, seeking Allah’s Pleasure.
In her belief and support for her husband, not only did she have to watch him suffer and then suffer herself, but she also had to witness her children undergoing difficulties only because their father was the true Prophet of Allah ﷺ.
The polytheists of Makkah wished to inflict as much pain upon Rasulullah ﷺ as they could. Hence, they approached his two sons-in-law, ‘Utbah and ‘Utaybah; and influenced them to divorce their wives, Ruqayyah and Umm Kulthum radiya Llahu ‘anhuma. Both brothers divorced their wives. Thus Sayyidah Khadijah RA had to endure the pain of two of her daughters being divorced, only on account of their father being the Nabi of Allah ﷺ.
When the persecution of the polytheists yielded them no results, and they saw Islam spreading despite all of their efforts, they adopted the idea of boycotting the Muslims. The boycott lasted for three years and it was certainly one of the most difficult periods endured by the Muslims. Sayyidah Khadijah RA was instrumental in easing the harsh effects of this boycott. Ibn Hisham says:
و بذلت رضى الله عنها مالها لتؤمن ما تستطيع من الطعام للمسلمين فى خلال سنوات المقاطعة
She spent her wealth in order to secure whatever food she could, for the Muslims during the years of the boycott. [Al Sirah al Nabawiyyah]
Her cousin, Hakim ibn Hizam (who accepted Islam after the conquest of Makkah) was the one who would discreetly bring the food to the Muslims. [ibid]