The voice of the first sign. Some understand "the voice of Moses as he gave them the first sign;" but it is better to regard the sign itself as speaking to them. According to the sacred writers everything that can teach us anything—day, night, the heavens, the firmament, the beasts, the fowls of the air, the fishes, nay, the very stones—have a voice.
They teach us, speak to us, declare to us, cry out aloud, lift up their voice, shout, sing, proclaim God's will, whether man will hear or whether he will forbear. (See Psalms 19:1-3; Job 12:7, Job 12:3; Habakkuk 2:11; Luke 19:40, etc.
) Equally, or rather much more, must a miracle be regarded as having a voice. God speaks to us by it.