The reference is to that even of Moses when sorcerers were sent for to confront him and they showed their sorcery by throwing ropes and sticks on the ground and Moses felt afraid. Thus, the Qur'an records:
. . . it seemed to him (Moses), by their sorcery as if they were running.Then Moses felt in himself a fear. We said: Fear not! Verily thou art the uppermost. (20:66-68)
