Kutoka 4 : 9 Exodus chapter 4 verse 9

Kisha itakuwa wasipoamini hata ishara hizo mbili, wala kuisikiliza sauti yako, basi, yatwae maji ya mtoni uyamwage juu ya nchi kavu, na yale maji uyatwaayo mtoni yatakuwa damu juu ya nchi kavu.
soma Mlango wa 4

It will happen, if they will not believe even these two signs, neither listen to your voice, that you shall take of the water of the river, and pour it on the dry land. The water which you take out of the river will become blood on the dry land."