Hadith 9400

وَقَالَ : " مَنْ تَوَلَّى قَوْمًا بِغَيْرِ إِذْنِ مَوَالِيهِ ، فَعَلَيْهِ لَعْنَةُ اللَّهِ وَالْمَلَائِكَةِ ، لَا يَقْبَلُ اللَّهُ مِنْهُ صَرْفًا وَلَا عَدْلًا " .
And he said: Whoever enters into a contract of allegiance with any people without the permission of his masters, upon him is the curse of Allah and all the angels. Allah will not accept any obligatory or voluntary act from him.
Hadith Reference مسند احمد / مسند المكثرين من الصحابة / 9400
Hadith Grading حکم دارالسلام: إسنادہ صحیح ، م : 1508