أَلَا كُلُّكُمْ رَاعٍ، وَكُلُّكُمْ مَسْئُولٌ عَنْ رَعِيَّتِهِ (Nasa'i; the full report is longer)
Translation: Take notice: each of you is a caretaker, and each of you will be questioned about those or that placed under your care.
أَلَا — pay attention; رَاعٍ — caretaker; مَسْئُولٌ — accountable; رَعِيَّتِهِ — those/that in one's care.
Brief grammar: كُلُّكُمْ رَاعٍ is a nominal sentence: كُلُّكُمْ is the subject and رَاعٍ its predicate. عَنْ is a preposition in عَنْ رَعِيَّتِهِ.
Responsibility is not limited to rulers: parents, teachers, workers, students, and those entrusted with authority each have duties toward people and tasks in their care.