Deuteronomy 29:3

The great temptations which thine eyes have seen
Or trials, the ten plagues which tried the Egyptians, whether they would let Israel go; and tried the Israelites, whether they would believe in the Lord, and trust in his almighty power to deliver them:

the signs and those great miracles:
as the said plagues were such as were beyond the power of nature to produce, and which only Omnipotence could really effect.