While the Prophet was in Makkah, the Persians attacked the Romans. Their battle took place between Azruat and Busra in Syria. During this war, the polytheists of Makkah wished victory to the Persians. Because they were allies of the Persians in shirk and idol worship. On the other hand, the sincere desire of the Muslims was that the Romans should be victorious. Because they were close to Islam in terms of religion and sect. But the fact is that the Persians won the war like then. They even conquered Constantinople and built a fireplace for worship. This was the last victory of the Persian king Parvez. Then its decline began and it was completely wiped out by the Muslims.
The polytheists of Makkah were overwhelmed with joy at this incident and began to embarrass the Muslims that those whom you supported had lost. The matter does not end here; On the contrary, just as the People of the Book were defeated by the Romans, so will you be defeated by us one day. The Muslims are sincerely sorry for this.
The first verses of Surah Room are about this event. These verses foretell that in a few years the Romans will be victorious against the Persians.
Meaning- Alif-Lam-Meem, the Romans have been defeated, in the vicinity and they will be victorious immediately after their defeat, in a few years. [Surah Room, verses 1-4]
When Abu Bakr Siddiq (may Allah be pleased with him) heard these verses, he declared that there was no reason for you to rejoice at the gatherings and markets of the polytheists around Mecca. Within a few years the Romans would have won against the Persians. Among the polytheists, Ubayy ibn Khalaf spoke and said, "You are lying." That cannot be the case. Hadrat Abu Bakr said, "You are the liar, the enemy of Allah." I am ready to bet for this event.
If the Romans do not win in three years, I will give you ten camels. Ubayy agreed. [Needless to say, it was gambling but gambling was not forbidden then] Abu Bakr (ra) appeared before the Prophet (peace and blessings of Allaah be upon him) and narrated the incident. The Prophet (peace and blessings of Allaah be upon him) said: I have not fixed the time for three years. So this can happen in three to nine years. You go and tell Ubayy that I am betting a hundred camels instead of ten, but the period is nine years instead of three, and according to some traditions seven years.
Hadrat Abu Bakr obeyed the order and Ubayy also agreed to the new treaty. According to various hadiths, this happened five years before the Hijrah, and seven years later, during the Battle of Badr, the Romans were victorious against the Pasik. Ubayy ibn Khalaf was not alive then. Hadrat Abu Bakr demanded a hundred camels from his heirs and collected them. Hazrat Abu Bakr (RA) won the bet and got a hundred camels. Then he came to the Messenger of Allah with them. He said, "Give alms to the camels."