Sayyiduna Ali (may Allah be pleased with him) said a few words which are upon the truth: It is obligatory upon the Imam to judge according to the command that Allah, the Mighty and Majestic, has revealed and to fulfill the trust. Then, when he does this, it is obligatory upon the people to listen to him, obey him, and when called, to respond with "Labbayk" (Here I am).
Hadith Referenceسنن سعید بن منصور / كتاب التفسير / 651
Hadith Gradingمحدثین:سنده صحيح.
Hadith Takhrij«أخرجه سعيد بن منصور فى (سننه) برقم: 651، وابن أبى شيبة فى (مصنفه) برقم: 33199»