Hadrat Imâm-i Rabbânî says in the 96th letter of the second volume of his Maktûbât:
May Allâhu ta’âlâ increase your understanding. May He bless you with the lot of walking on the right way!
If those who strive to denigrate the three Khalîfas and the other Sahabîs by bringing forward such doubts become reasonable and realize the honour and value of the sohbat of the Best of Mankind and if they know that the Sahâba ‘alaihimurridwân’ had gotten rid of the desires of their nafs completely and had been purified from such bad habits as grudge and enmity by benefiting from this sohbat; that they were all great men of Islam and Islam’s eye-apples; that they strove with their utmost to strengthen Islam and to help the Best of Mankind, that they sacrificed all their property to exalt Islam; that they left and sacrificed their clans and tribes, their children and wives, their homes and homelands, their waterways, fields, trees and rivers, for their excessive love of Rasûlullah ‘alaihissalâm’, that they loved Rasûlullah ‘sallallâhu alaihi wa sallam’ more than their own lives; that they were honoured with seeing the wahy, the angel; that they saw miracles and wonders; that they realized by seeing what should be believed without seeing; that what is knowledge for others was experience for them; and that they are praised and lauded by Allâhu ta’âlâ in the Qur’ân, they will realize that these doubts are sheer fibs, and they will pay no heed to them.
They will not even consider it necessary to find out the unsound places in these fibs or to eliminate the wrong points in them. All the Sahâba have this superiority.
How could we ever describe the superiority of the Khulafâ-i râshidîn, the four Khalîfas, who are the most superior among them?