As and when Moses (Hazrat Musa A.S) reached the Divine Domain, he was asked, what is in your right hand:
And what is that in your right-hand, O Moses? (20:17)
Moses was put this question on Mount Sanai, where he saw the Divine Light and got Divine Commandments. He answered:
He said, "This is my staff. I lean on it, and herd my sheep with it, and I have other uses for it." (20:18)
Prophets of People of the Book (Ahl-e-Kitab) were destined to be shepherds, which as per the events that followed was the training ground for shepherding the flock of their followers on being entrusted with Prophethood. The staff of Moses (Ase-e-Musa) with which he would herd his flock was to develop in time other uses as per the divine command.
The flock of Moses–the Hebrews, known also as Israelites (Beni Israel: Israel being one of the attributes of Jacob [Hazrat Yaqub A.S]) were subjects of Pharaoh. Living under tyrannical rule, and facing harsh conditions, they developed traits subject people are prone to.