The staff of the wicked probably refers to a stick that wicked people would hit other people with. Breaking that stick represents destroying their power to treat people cruelly. AT: "Yahweh has destroyed the power of the wicked" (See: [[rc://en/ta/man/translate/figs-metonymy]])
A scepter represents a ruler's power to rule. Breaking the scepter represents destroying the ruler's power. AT: "Yahweh has destroyed the power of the wicked rulers" (See: [[rc://en/ta/man/translate/figs-metonymy]])