These are nearly all the public acts related by historians in which Muhammad took part in the first fifteen years of his marriage to Khadijah. As for his private life he is described to have been ever helpful to the needy and the helpless. His uncle, Abu Talib, had fallen into distress through his endeavors to maintain the old position of his family. Muhammad, being rather rich at this time by his alliance with Khadijah, tried to discharge part of the debt of gratitude and obligation which he owed to his uncle by undertaking the bringing up and education of his son Ali. A year later he adopted Akil, another of his uncle's sons.
Khadijah bore Muhammad three sons and four daughters. All the males died in childhood, but in loving Ali he found much consolation.
Zaid, Muhammad's Son
About this time Muhammad set a good example of kindness, which created a salutary effect upon his people. His wife Khadijah had made him a present of a young slave named Zaid Ibn Haritha, who had been brought as a captive to Mecca and sold to Khadijah. When Haritha heard that Muhammad possessed Zaid, he came to Mecca and offered a large sum for his ransom. Whereupon Muhammad said: "Let Zaid come here, and if he chooses to go with you, take him without ransom; but if it be his choice to stay with me, why should I not keep him?" Zaid, being brought into Muhammad's presence, declared that he would stay with his master, who treated him as if he were his only son. Muhammad no sooner heard this than he took Zaid by the hand and led him to the black stone of Kaba, where he publicly adopted him as his son, to which the father acquiesced and returned home well satisfied. Henceforward Zaid was called the son of Muhammad.
Muhammad and Meditation
Muhammad was now approaching his fortieth year, and his mind was ever engaged in profound contemplation and reflection. Before him lay his country, bleeding and torn by fratricidal wars and intolerable dissensions; his people, sunk in barbarism, addicted to the observation of rites and superstitions, were, with all their desert virtues, lawless and cruel. His two visits to Syria had opened to him a scene of unutterable moral and social desolation, rival creeds and sects tearing each other to pieces, carrying their hatred to the valleys and deserts of Hijaz, and rending the townships of Arabia with their quarrels and bitterness.
For years after his marriage, Muhammad had been accustomed to secluding himself in a cave in Mount Hira, a few miles from Mecca. To this cave he used to go for prayer and meditation, sometimes alone and sometimes with his family. There, he often spent whole nights in deep thought and profound communion with the Unseen yet All-Knowing Allah of the Universe. It was during one of those retirements and in the still hours of the night, when no human sympathy was near, that an angel came to him to tell him that he was the Messenger of Allah sent to reclaim a fallen people to the knowledge and service of their Lord.