In the old testament is says
1. The Lord leads his people out of Egypt
2. An angel with the name in him of Lord leads his people out of Egypt.
3. The presence of the Lord lead his people of Egypt.
It's the odd interchangeability of these statements which lead to the idea of the diety of Jesus.
Also the old testament is full of statements like " the angel of the jehovah appeared and jehovah said " or " the word of the jehovah appeared and jehovah said.
YouTube Jesus in the old testament by Michael heiser. It's pretty cool stuff. It really shows how the old and new testaments are connected and how it's really is the story of God and Jesus from beginning to end.