Sermon (144): When Umar ibn al-Khattab Asked for Advice from Him (peace be upon him) Regarding Participation in the War Against Persia, He Said
In this matter, success and failure do not depend on the increase or decrease of the army. This is Allah's religion, which He has kept dominant (over all religions), and this is His army, which He has prepared, and He has helped it in such a way that it has advanced to its present limit and spread to its present extent. And we have a promise from Allah, and He will fulfill His promise and will help His army Himself. In matters (of state), the ruler has the same position as the string in beads, which keeps them gathered. When the string breaks, all beads will scatter, and then they will never be able to gather again. Today the Arabs, although few in number, are many because of Islam, and are victorious and dominant due to mutual unity. You should remain firm on your position like a peg, and maintain the order and system of the Arabs, and let them face the fire of war. For if you leave this land, the Arabs will attack you from all sides, until you will be more worried about those places that you left unprotected behind you than about the situations before you. Tomorrow, if the non-Arabs see you, they will (say to each other) say: 'This is the chief of the Arabs.' If you destroy their fortress, you will be satisfied, but because of this, their greed and covetousness toward you will increase. But as for what you say that those people have set out to fight and clash with the Muslims, Allah considers their advancement worse than you do, and He has great power to change (and stop) what He considers bad. And regarding their number that you mention (that they are many), we did not fight in the past on the strength of numbers, but on (Allah's) support and help.
