Used of persons evenly matched in wit or cunning. Also frequently found as a descriptive phrase
diamond cut diamond.
Cf.
1593
NASHE
Christ's Tears
II. 9 An easie matter is it for anie man to cutte me (like a Diamond) with mine own dust.
1604
Malcontent
IV. i.
None cuttes a diamond but a diamond.
1629
Lover's Melancholy
I. 18.
We're caught in our own toyles. Diamonds cut Diamonds.
1863
Hard Cash
II. xi.
You might say I robbed you … It is diamond cut diamond.
1958
Nine Coaches Waiting
xi.
I'll always have prospects. Diamond cuts diamond.
1979
Guardian
19 Apr. 26
When the boat comes in:
Diamond cut diamond. James Bolam as the rough one turned smoothie.
similarity and dissimilarity