He listens well
Who takes notes.

[Bene ascolta chi la nota.]

Dante Alighieri the poet
Dante Alighieri (1265-1321) Italian poet
The Divine Comedy [Divina Commedia], Book 1 “Inferno,” Canto 15, l. 99ff (15.99) (1309) [tr. James (2013)]
    (Source)

Virgil either warning Dante to consider all the predictions / warnings he's receiving from the damned about "future" political troubles, or else praising him for appearing to have remembered them (interpretations vary).

(Source (Italian)). Alternate translations:

He listens well, who what he hears remarks.
[tr. Rogers (1782), l. 96]

"Unhappy is the man," exclaim'd my Guide,
"From whose weak mind the words of wisdom glide."
[tr. Boyd (1802), st. 18]

He listens to good purpose who takes note.
[tr. Cary (1814)]

Well doth he hear, who marks what he hath heard.
[tr. Dayman (1843)]

He listens well who notes it.
[tr. Carlyle (1849)]

He listens well who notes.
[tr. Bannerman (1850)]

He listens well who noteth well.
[tr. Johnston (1867)]

He listeneth well who noteth it.
[tr. Longfellow (1867)]

Well listens he who marks it.
[tr. Butler (1885)]

Who noteth well, he well doth hear.
[tr. Minchin (1885)]

He listens well who notes it.
[tr. Norton (1892)]

He listeneth well that layeth it to heart.
[tr. Sullivan (1893)]

He listens well who notes the matter.
[tr. Griffith (1908)]

He is a good listener who takes note.
[tr. Sinclair (1939)]

He listens well who noteth well the word.
[tr. Binyon (1943)]

Well-heeded is well-heard.
[tr. Sayers (1949)]

Well heeded is well heard.
[tr. Ciardi (1954)]

He who notes it listens well.
[tr. Singleton (1970)]

He listens well who notes well what he hears.
[tr. Musa (1971)]

He who takes note of this has listened well.
[tr. Mandelbaum (1980)]

Those are the words of a good listener!
[tr. Sisson (1981)]

He who has listened well will understand.
[tr. Pinsky (1994)]

He listens well who takes note.
[tr. Durling (1996)]

He listens closely, who notes it.
[tr. Kline (2002)]

"Those listen well," he said, "who take good note."
[tr. Kirkpatrick (2006)]

He listens well who takes in what he hears.
[tr. Hollander/Hollander (2007)]

It's good
To hear such words, for they are truly profound.
[tr. Raffel (2010)]