I can say nothing more than my understanding of when to take verses literally or metaphorically is when it is unnatural. Throwing a stick down and eating the sticks/snake of others is far from natural but if you wish to believe this then each to their own.
7:104 Moses said, "O Pharaoh! I am a Messenger from the Lord of the Worlds.
7:105 It is incumbent upon me that I say about God nothing but the truth. I come to you with clear evidence of the truth from your Lord. So let the Children of Israel go with me.”
7:106 Pharaoh said, “If you have come with clear evidence, produce it if you are of the truthful.”
7:107 Moses presented his argument that he held fast, with vibrant confidence and logic.
7:108 The strength of his conviction shone bright to those present. [20:17-21]
7:109 The chiefs of Pharaoh's nation said, "This is some knowing wizard!
7:110 It appears to us that Moses, after gaining some following, plans to throw you out of your land.” Said Pharaoh, “Now, what do you advise?”
7:111 (After consulting) they said, "Put him and his brother off for a while and send to the cities men to summon.
7:112 To bring all debaters to your court.” [Saahir from Sihr = Magician, liar, stunningly eloquent, smart poet, deceitful, trickster, cheater, defrauder, dodger, hoaxer, swindler]
7:113 The debaters came to Pharaoh. They said, “Will there be reward for us if we are victors?”
7:114 He answered, “Yes, and you will be among those who are close to me.”
7:115 The debaters said, “O Moses! Either you begin or let us be the first to present our case.”
7:116 Moses asked them to begin. When they began they cast a spell on the people’s eyes, and struck them with awe, and stunned the assembly with their spellbinding eloquence.
7:117 So, We inspired Moses, “Respond with conviction. And then see how it swallows their deceptive rhetoric.” [‘Asaa = Staff = Cane = Strength = Conviction = Authority = Power = Strong logic = Convincing argument]
7:118 The truth prevailed and their arguments were manifestly proven false.
7:119 Thus, they were defeated right there and humiliated.
7:120 The debaters fell down prostrate.
7:121 They were convinced and said, "We believe in the Lord of the Worlds.
7:122 The Lord of Moses and Aaron.”