If I may be his guide, you’ll lose him yet;
I’ll subtly lead him my way, if you’ll let
Me do so; shall we have a bet?

[Was wettet Ihr? den sollt Ihr noch verlieren!
Wenn Ihr mir die Erlaubnis gebt,
Ihn meine Straße sacht zu führen.]

Johann Wolfgang von Goethe (1749-1832) German poet, statesman, scientist

Faust: a Tragedy [eine Tragödie], Part 1, sc. 3 “Prologue in Heaven,” l. 320ff [Mephistopheles] (1808-1829) [tr. Luke (1987)]
    (Source)

Mephisto to the Lord, on tempting His servant, Faust.

Some translations (and this site) include the Declaration, Prelude on the Stage, and Prologue in Heaven as individual scenes; others do not, leading to their Part 1 scenes being numbered three lower.

(Source (German)). Alternate translations:

What will you wager? Him you yet shall lose,
     If you will give me your permission
     To lead him gently on the path I choose.
[tr. Priest (1808)]

What will you bet? -- now I am sure of winning --
Only, observe you give me full permission
To lead him softly on my path.
[tr. Shelley (1815)]

What will you wager? you shall lose him yet, if you give me leave to guide him quietly my own way.
[tr. Hayward (1831)]

What wilt thou wager? Him thou yet shall lose,
If leave to me thou wilt but give,
Gently to lead him as I choose!
[tr. Swanwick (1850)]

What will you bet? You'll surely lose your wager!
If you will give me leave henceforth,
To lead him softly on, like an old stager.
[tr. Brooks (1868)]

What will you bet? There's still a chance to gain him,
If unto me full leave you give,
Gently upon my road to train him!
[tr. Taylor (1870)]

What wager you? you yet shall lose that soul!
Only give me full license, and you’ll see
How I shall lead him softly to my goal.
[tr. Blackie (1880)]

What will you wager? Give me but permission
To lead him gently on my way,
I'll win him from you to perdition.
[tr. Latham (1908)]

What will you bet? You'll lose him yet to me,
If you will graciously connive
That I may lead him carefully.
[tr. Kaufmann (1961)]

What will you bet? You'll lose him in the end, if you'll just give me your permission to lead him gently down my street.
[tr. Salm (1962)]

You'll lose him yet! I offer bet and tally,
Provided that your Honor gives
Me leave to lead him gently up my alley!
[tr. Arndt (1976)]

Would you care to bet on that? You'll lose, I tell you,
If you'll give me leave to lead the fellow
Gently down my broad, my primrose path.
[tr. Greenberg (1992)]

What would you wager? Will you challenge me
To win him from you? Give me your permission
To lead him down my path to his perdition?
[tr. Williams (1999)]

What do you wager? I might win him yet!
If you give me your permission first,
I’ll lead him gently on the road I set.
[tr. Kline (2003)]