Exodus 4:9-11

New Revised Standard Version, Anglicised Catholic Edition

⁹ If they will not believe even these two signs or heed you, you shall take some water from the Nile and pour it on the dry ground; and the water that you shall take from the Nile will become blood on the dry ground.’

¹⁰ But Moses said to the Lord, ‘O my Lord, I have never been eloquent, neither in the past nor even now that you have spoken to your servant; but I am slow of speech and slow of tongue.’ ¹¹ Then the Lord said to him, ‘Who gives speech to mortals? Who makes them mute or deaf, seeing or blind? Is it not I, the Lord?