What does Exodus 8:4 Mean?

Context Summary

Probably the plagues followed in rapid succession, so that the impression of one had not passed away before another succeeded. The whole conflict was probably comprehended in nine or ten months. The frog was a goddess, hence the plague was aggravated, as it was unlawful to destroy one. This stroke elicited the first symptom of surrender. Though the magicians counterfeited the coming of the frogs they failed to remove them, and the king did not hope for such help from them. Pharaoh implored the intercession of the great Hebrew brethren, who, to make the power of God and the efficacy of prayer more manifest, asked the king to fix the time. They who know God and obey Him absolutely can reckon on Him with perfect certainty and confidence. Our God delights in the faith that dares to pledge His willingness and power, and He will not fail the soul that ventures wholly on His all-sufficiency. [source]

Chapter Summary: Exodus 8

¹  Frogs are sent
⁸  Pharaoh complains to Moses, who by prayer removes them
¹⁶  The dust is turned into lice, which the magicians could not do
²⁰  The plague of flies
²⁵  Pharaoh inclines to let the people go, but yet is hardened