Al-Matalib al-'Aliyah 3680 — Surah al-Rum

It is narrated from Sayyiduna al-Bara' bin Azib (may Allah be pleased with him) that when this saying of Allah Almighty was revealed: "Alif Lam Mim. The Romans have been defeated in the nearest land" [Surah al-Rum: 1-3], some people of Makkah met Sayyiduna Abu Bakr al-Siddiq (may Allah be pleased with him) and said: "Do you not consider what your companion (that is, the Prophet, peace and blessings be upon him) says? He claims that the Romans will soon overcome the Persians." Sayyiduna Abu Bakr al-Siddiq (may Allah be pleased with him) replied: "The Messenger of Allah (peace and blessings be upon him) has spoken the absolute truth." They said: "Then will you make a wager with us on this?" He said: "Yes." Sayyiduna Abu Bakr (may Allah be pleased with him) relates that when this reached the Messenger of Allah (peace and blessings be upon him), he (peace and blessings be upon him) asked: "What did you intend by this (wager)?" He said: "O Messenger of Allah! I did this only to affirm and support the truth of Allah Almighty and His Messenger (peace and blessings be upon him)." He (peace and blessings be upon him) said: "Go to them again, increase the stake of the wager, and set its term as 'bid' sinin' (that is, between three and nine years), for before these years pass the Romans will certainly prevail over the Persians." So Sayyiduna Abu Bakr al-Siddiq (may Allah be pleased with him) passed by them and asked: "Would you be interested in wagering again? For going back again is better." They said: "Yes." Then they made the agreement with him again and increased the stake.
Those appointed years had not yet ended when the Romans overcame the Persians. So Sayyiduna Abu Bakr (may Allah be pleased with him) collected the stake and brought it to the noble presence of the Prophet (peace and blessings be upon him), and the Messenger of Allah (peace and blessings be upon him) said: "This (money) is for excellent, finely bred riding camels."