Deuteronomy 4:34

Or hath God assayed to go and take him a nation from the
midst of another nation
As he now had done, namely, the nation of Israel out of the nation of the Egyptians; this he not only had assayed to do, but had actually done it; whereas no such instance like it could be produced, and especially as done in the manner this was:

by temptations, by signs, and by wonders, and by war;
the word "temptations" may be considered as a general word, as Aben Ezra thinks, and may signify the temptations by signs or the various essays and trials, ways, means, and methods taken by the Lord to bring about the event; by "signs" may be meant those which were required of Moses, and done by him before the people of Israel, and before Pharaoh, as proofs of his mission from the Lord, ( Exodus 4:1-9 Exodus 4:30 ) ( 7:9 ) and by "wonders", the ten plagues of Egypt, which were done by a supernatural and miraculous operation, and were amazing things; see ( Psalms 78:11-13 ) ; and by "war", either the slaying of the firstborn, with the destruction of the judges and gods of Egypt, as Aben Ezra; or the Lord's fighting for Israel at the Red sea, as Jarchi; he saved them and destroyed the Egyptians, and showed himself to be a man of war, ( Exodus 14:14 Exodus 14:25 ) ( 15:3 )

and by a mighty hand and stretched out arm;
phrases frequently used when this affair is spoken of, and are expressive of the mighty power of God in the above instances, and in the issue of them, bringing Israel out of Egypt; though Aben Ezra interprets it of the pillar of fire and cloud in which the Lord went before them:

and by great terrors;
which the same writer interprets of the drowning of Pharaoh and his host in the sea, and dividing it for Israel; but may be understood not only of the terrors which possessed him and his people then, but at other times, especially at the time of the thunder and lightning, and when they sat in thick darkness, and particularly when all their firstborn were slain; see ( Deuteronomy 26:8 ) ,

according to all that the Lord your God did for you in Egypt before
your eyes;
among the men of Egypt, as the above writer, Pharaoh and his courtiers: the above things were done as before them for their terror, so before Israel for their encouragement.