A Well-Known Saying

[hiflier]

'To know something like the back of your hand.' I have looked in many reference books but have never found a plausible explanation of this phrase. Since I doubt that most people would actually be able to identify a picture of their own hand from a selection of the same I think we may have to think outside the box to get a handle on the origin of this saying. Any suggestions?

[DTCwordfan]

from etymonline

To know (something) like the back of one's hand, implying familiarity, is first attested 1893 in a dismissive speech made to a character in Robert Louis Stevenson's "Catriona":

If I durst speak to herself, you may be certain I would never dream of trusting it to you; because I know you like the back of my hand, and all your blustering talk is that much wind to me.
The story, a sequel to "Kidnapped," has a Scottish setting and context, and the back of my hand to you was noted in the late 19th century as a Scottish expression meaning "I will have nothing to do with you" [see Longmuir's edition of Jamieson's Scottish dictionary]. In English generally, the back of (one's) hand has been used to imply contempt and rejection at least since 1300. Perhaps the connection of a menacing dismissal is what made Stevenson choose that particular anatomical reference.

[Chinajan]

Potentially we're talking about two separate sayings though DTC.

The reference cited is just to 'the back of my hand' apparently used in a context of showing the back of a hand to be dismissive.

What we're addressing in this thread is the specific meaning of 'to know [something] like the back of one's hand'. Quite different.

[Jackdaw33]

Hiflier's explanation is very good, except for one thing: the unseen part of a card is the back, not the face.

[Chinajan]

Good point jackdaw - and further evidenced by OP saying 'face down' in the explanation of the theory.

[Canary42]

Perhaps you should ask Boris, he's very fond of back-handers.

[OK, I'll get my coat]