Surah 20. Ta-Ha, Ayah 20

Cf. vii. 107, where a different word (thu'ban) is used for "snake", and the qualifying adjective is "plain (for all to see)". The scene there is before Pharaoh and his magicians and people: the object is to show the hollowness of their magic by a miracle: the rod appears before them as a long and creeping writhing serpent. Here there is a sign to present Allah's power to Moses's mind and understanding: the rod becomes a Haiy (a live snake), and its active motion is what is most to be impressed on the mind of Moses, for there were no other spectators.