A Second Letter Of Advice From ‘Umar Ibn Al-Khattaab To Sa’d Ibn Abee Waqqaas Before The Battle Of Qaadisiyyah (14 H)
After Sa’d Ibn Abee Waqqaas had left Madeenah and was camping near Zarood in preparation for the decisive battle with the Persians, ‘Umar Ibn Al-Khattaab sent him another letter telling him to set out to Iraaq. In this letter ‘Umar said:
“I am ordering you and the troops who are with you to fear Allaah in all circumstances, for fear of Allaah is the best weapon against the enemy and the strongest weapon in war. I am commanding you and those who are with you to be more careful in avoiding sin than in avoiding your enemy, for the sins of the army are to be feared more than their enemy. The Muslims are supported by their enemy’s disobedience towards Allaah. Were it not for that, we would not have any strength, for our numbers are not like theirs and our weapons are not like theirs. If we were equally matched in sin, they would have an advantage over us in strength, and if we did not have an advantage over them by virtue, we would not be able to defeat them by our strength.
Remember that you have over you protectors from Allaah who know what you are doing, so feel shy before them and do not do any act of disobedience towards Allaah. You are striving for the sake of Allaah, do not say that our enemy is worse than us and will never prevail over us even if we will commit sins. A people may be defeated by others who are worse than them, just as the children of Israel were defeated by the kaafir Magians when they did deeds that angered Allaah, and:
“…They entered the very innermost parts of your homes. And it was a promise [completely] fulfilled.” [17:5]
Ask Allaah for help against your evil whims and desires just as you ask Him for help against your enemies. I ask Allaah for that, for us and you.
Be kind to the Muslms on their march. Do not exhaust them on their march, lest they reach their enemy weakened from their journey, for they are marching towards an enemy that has not been travelling, that has strong horses and riders. You and those who are with you should rest for one day and night every week, so that they will be able to regain their strength and lay down their weapons and belongings.
Do not camp near the towns of people who have a treaty with us or are under our protection, and do not let any of your companions interact with them except those whose religious commitment you are confident of. Do not annoy any of the townspeople at all, for they are protected and you are being tested with regards to fulfilment of the treaty, just as they are being tested with regard to their patience in adhering to it. So long as they are keeping their promise to you, keep your promise to them. Do not seek victory against your enemies by oppressing those with whom you have a treaty.
When you reach the closest point of enemy land, send out spies, for none of their affairs should be hidden from you. You should have with you Arabs and local people whom you trust and who you feel are sincere, for the news of a liar will be of no benefit to you, even if he tells the truth sometimes. The dishonest one is a spy against you, not for you.
When you draw closer to the enemy’s land you should send out scouts and raiding parties to cut their supply lines and try and fond out their weak points. Choose people of wisdom and strength among your companions for these missions, and choose the best horses. If they see the enemy the best way to deal with them is by means of good advice from these people.
Put the people of jihaad, patience and toughness in charge of these raiding parties, and do not show favour to anyone on the basis of whims and desires, because this may affect the whole affair and lead to bad consequences. Do not send out any scouts or raiding parties in a direction in which you fear they may be exposed to danger. If you sight the enemy, then bring back your scouts and troops.
But do not hasten to engage in fighting unless you are forced to, until you have had the opportunity to find out their fatal weak points and have studied the land until you know it as well as its people do.
If any prisoner is brought to you with whom you do not have a treaty, you should execute him so as to strike fear into your enemies and the enemies of Allaah.
Allaah is the best disposer of affairs for you and those who are with you. He is the One Who grants victory to you over your enemy, and Allaah is the One Whose help we seek.”
[Al-Faarooq ‘Umar Ibn Al-Khattaab, by Muhammad Rasheed Rida, Pp. 119-120]