Is the statement attributed to Imam Ahmad ibn Hanbal, "It is a sign of the Murji’ah that they describe the people of Sunnah as Khawarij," authentic?

We have not come across any attribution of the saying: "If the People of the Sunnah were safe from the Khawārij and the Murji'ah, they would have found peace," to Imam Ahmad, even though it has been attributed to him. There is nothing strange about this statement, for it is true and reflects reality. The Murji'ah accuse the People of the Sunnah of being Khawārij, and the Khawārij accuse them of being Murji'ah. However, the People of the Sunnah are a moderate path between these two deviant sects. As Ibn Taymiyyah said: "Islam is a moderate path among the religions, between the contending extremes, and the Sunnah within Islam is like Islam among the religions." The People of the Sunnah, in the chapter of names and rulings (al-asmā’ wa’l-aḥkām), are moderate, standing between the Khawārij, the Mu'tazilah, and the Murji'ah. What they endure from these two sides will not harm them.