“ And I brought your fathers out of Egypt, and you came to the sea, and the Egyptians pursued after your fathers, with chariots and horsemen, to the Sea of Reeds, and when they cried to YHWH he put darkness between you and the Egyptians, and brought the sea on them, and covered them. And your eyes saw what I did in Egypt, and you dwelt in the wilderness many days.”
The scene was now passing to events that some of the elders among them had themselves experienced as children. YHWH declared how he brought their fathers out of Egypt and delivered them through the deliverance of the Sea of Reeds, and He reminds them of the wonders they themselves had seen in Egypt, the darkness he brought to hide them from the Egyptians (Exodus 14:20), and how He destroyed the Egyptians in the sea (see Exodus 14-15). Then they dwelt in the wilderness many days, preserved by YHWH Who gave them their provisions from heaven.
“I brought you out and I brought your fathers out.” This is very telling. The first phrase emphasises that there are eyewitnesses still present among them while the second remembers that they were but children at the time.