AMBASSADOR Such as I am, I come from Antony.
I was of late as petty to his ends
As is the morn-dew on the myrtle leaf
To his grand sea.
CAESAR Be’t so. Declare thine office.
AMBASSADOR Lord of his fortunes he salutes thee, and
Requires to live in Egypt; which not granted,
He lessens his requests, and to thee sues
To let him breathe between the heavens and earth,
A private man in Athens. This for him. (3.12.7-15)
The ambassador doesn’t have any choice, really; he has to grovel. But he’s trying to retain some shreds of dignity, for himself and also for Antony, and so there are some (probably ill-advised) rhetorical flourishes. Such as I am, I come from Antony. That’s me, humble and unassuming; any status I have is only derived from my mission. And I was of late as petty to his ends as is the morn-dew on the myrtle leaf to his grand sea. I’m nobody, really! And until recently I was nobody to Antony too, as insignificant in his schemes and projects as a tiny, tiny dewdrop is in comparison with an ocean. I’m the dewdrop, he’s the sea. I’ve got no influence, no status! (The subtext here is, partly, one which has become familiar in the play: don’t shoot the messenger! And this messenger is the most precarious in his position of any emissary so far encountered.) Yeah, ok, whatever, says Caesar, be’t so. As always, he’s impatient with flannel and flattery: cut to the chase! Declare thine office, make your case and get on with it. Stop wasting my time I am very busy and important.
The schoolmaster is either providing a courteous, conciliatory gloss on what Antony has authorised him to say or else he’s relaying it word for word, as a messenger should. (Given Antony’s impatience with the boy Caesar, the former seems likely.) But the terms for which he’s suing are clear, and the expression flattering and correct. Lord of his fortunes, he salutes thee: greetings! you’ve got the power, you hold his future, good or bad, in your hands. (Antony is perhaps quibbling, carefully: he’s not addressing Caesar as his lord, he’s not pledging his loyalty or giving up his own claims, or not in so many words. Antony’s merely saying, in effect, well, you won, you lucky bastard. And good day to you.) He requires— requests—to live in Egypt. (It’s not necessarily a demand but this is, implicitly, a final and definitive rejection of the marriage with Octavia.) If you won’t let him live in Egypt, well, fine, but in that case, which not granted, he’ll compromise, he lessens his requests, and to thee sues to let him breathe between the heavens and earth, a private man in Athens. Just let him live, in quiet, peaceable retirement, in Athens. That’s all he’s asking. He won’t be any trouble. You can leave him alone, leave him to his own devices. It’ll all be fine. This for him.