1)
What is the metaphor of bearing morning wings?
1.
Rashi: If I would bear wings like the morning, which illuminates from one end of the world to the other, so I would hasten to fly to where I can dwell, "at the end of the sea."
2.
Radak: If I would say to take morning wings and fly with them...
3.
Malbim: If I would have a wing to fly from east to west in one day, and not lodge until I reached "the end of the sea..."
2)
What is "Acharis Yam"?
1.
Radak: It is the west, i.e. the end of the world, for the sea surrounds the world. Even if I could go there in one moment, I cannot go without You.