I have come to know of your anger at the posting of al-Ashtar in your place, but I did not do so because of any shortcoming on your part or to get you to increase your efforts, but when I had taken away what was under your authority I would have placed you at a position which would have been less exacting and more attractive to you.
The man whom I have made Governor of Egypt was my well-wisher, and very severe and vengeful towards our enemies. May Allah have mercy on him, as he has finished his days and met his death. I am quite pleased with him. May Allah too accord him His pleasure, and multiply his reward. Now get ready for your enemy and act according to your intelligence. Prepare for fighting him who fights you and calling to the path of Allah. Seek Allah's help exceedingly. If Allah wills He will assist you in what worries you and help you with what befalls you.