Why did the children of Israel believe Moses when he came to them?
Israel believed Moses because they witnessed the signs God enabled him to perform. When Moses threw down the rod and it became a serpent, and performed another miracle, the people saw these confirming wonders and accepted that God had sent him. Their belief rested on visible miraculous evidence, not merely on Moses’ words.
Les explains that as Moses approached the children of Israel, he did what God told him to do: he threw down the rod, and it became a serpent. He performed another miracle, and the next verse records that they believed. The reason given is that they saw the signs. Les points out that this pattern runs all the way up through Israel’s history, and Jesus spent three years performing signs and miracles up and down the land of Israel to prove to those Jews who He really was.