It was only after the conquest of Makkah that the Prophet sent Amr bin Aas to the joint rulers of Oman, the two brothers Abd and Jayfar. All his previous letters to rulers, near and far, had been sent immediately after the Treaty of Hudaybia. In this letter, the Prophet informed the two brothers of his mission to acquaint men with the truth of Islam and the dangers of disbelief. He warned them that if they rejected Islam, they would pay in this world and the next, for Islam would prevail.

Abd was the first one to meet with Amr, and they talked at great length. “What is your message?” Abd asked. “We call people to Allah, Who is One, Peerless, and we ask them to abandon all other deities and to bear witness that Muhammad is the servant and Messenger of Allah,” Amr explained. Abd posed a question, “What does your prophet enjoin?”

Amr replied, “He commands us to obey Allah and forbids us to disobey Him. He ordains good deeds, kindness to kith and kin, and prohibits excesses, adultery, liquor and the worship of stones, idols and the crucifix.”

Abd confided, “What a good thing he calls us towards! Had my brother also supported me, we would have set out to pledge fealty to Muhammad and to testify as to his Prophethood. Unfortunately, my brother is fond of his kingship than of obeying another.”

Amr said: “If your brother accepts Islam, then the Prophet will keep his kingdom intact. However, he will take some wealth by way of collecting charity from the rich and distribute it to the poor and needy.”

Abd commented, “That is very nice.” Then he asked, “What is charity?” Amr explained the concept to him in detail. However, when Amr referred to the possession of livestock being subject to Zakaah, or wealth tax, Abu said doubtfully, I don’t know whether my people will accept that,”

Abd then took Amr bin As to his brother, Jayfar, who was also given the letter. Jayfar asked Amr as to what the Quraysh had done. “They all accepted Islam, and if you embrace Islam, you will be safe, or else our cavalry will trample your land and wipe out its greenery.”

Jayfar asked for a day’s reprieve, and on the following day he made a show of his military power. Nevertheless, he consulted with his brother in private, and the next day both brothers accepted Islam, and left Amr free to collect charity. They helped him against those who opposed the collection.