What is the exclamation "have at you" actually saying?

Solution 1:

Webster's 3rd New Int'l Dictionary gives it as

have at
to go at or deal with, usu. hostilely <flops the morning bale of poetry upon my desk and I pull up my chair to have at them> —H. L. Mencken

This is undoubtedly derived from the following sense of have:

10a to maneuver into a position of disadvantage or cause to be at a disadvantage.

Solution 2:

"Have at you" seems to be an elliptic formula from fencing comparable to French "En garde!". So I would assume that after "have" a noun is lacking, maybe "guard":

"Have guard at you!" (?)

I think in commented Shakespeare editions such a formula should be explained. Maybe that the use of the formula was extended to situations similar to fencing.

Romeo and Juliet, act 1, scene 1, line 60

TYBALT

What, drawn, and talk of peace? I hate the word,

As I hate hell, all Montagues, and thee.

Have at thee, coward!

(They fight.)

In the modern text of Sparknotes the line "Have at thee, coward!" is translated with: Let's go at it, coward!

http://nfs.sparknotes.com/romeojuliet/page_12.html

Well, that's the meaning, but no explanation of the elliptic formula. I've done some research now, but found only explanations of the meaning. "Have at thee!" is understood as Shakespearean expression for "Let's begin the fight!". So in Urban Dictionary or genius.com. Nobody seems to see that the ellipsis in Shakespeare's formula needs an explanation. I'll keep this problem in mind.

I've just found the following Melville quote:

To the last, I grapple with thee;

From Hell's heart, I stab at thee; For hate's sake, I spit my last breath at thee.

Herman Melville

http://www.brainyquote.com/quotes/quotes/h/hermanmelv390294.html

So it might be possible that "a stab" is lacking: Have a stab at thee. Not very convincing, though.

Or is it "Have my sword at thee"/Have the fight at thee"? Or: Here, have death looking at thee?

Here'a link to phrasefinder. They quote OED. The explanation is a bit lame. http://www.phrases.org.uk/bulletin_board/57/messages/1037.html