| Quote #1
I have now come here
The messenger has come to the lady hoping to effect a change in her state of mind. He wants her to feel sure of her lord's love. Here he promises that the lady will feel that way. He's very sure of himself, this guy (or piece of wood).
| Quote #2
I dare promise
Saying that he "dare" promise the lady's going to find a commitment in her and her lord's heart acknowledges that the outcome of his message is far from certain, despite the confidence of the previous lines.
| Quote #3
Begin to seek the ocean, the native land of seagulls,
Saying that her lord is already "in expectation" of her implies that he, like the speaker, is optimistic about the effect his message will have upon the lady.