Millions of birds i.e. seekers lived and dyed their wings. Later they used the wooden planks as foot-holds and thereby landed from the boats on shore. (This means that they lived and used the conventional method of Sharah.) Some of them collected rubies and some merely dyed their wings red. The goose (i.e. the Prophet of Islam) joined the Beloved (i.e. died) after leaving behind millions of his followers.
Note: The verse signifies the achievement of various true believers in different ways. Some became distinguished saints, while others had a little distinction.

Some of the birds some emrgel from the turbit water,
Some collected pearls, some had their feathers crimsoned,
With lakhs in too, the swan joined the beloved.