Learn English – Origin of “sleep like a baby”

idiomsphrase-requests

I believe that many, or in fact, most of you have heard the phrase "sleep like a baby". But actually, where does the phrase originate from? Personally, I don't think using baby is a good reference as babies usually wake up crying at night or wake up and scream every 3 hours asking for milk.

I would like to ask why is the reference for babies used instead of other, possibly better references like 'sleep like a patriarch', for instance?

Best Answer

This should be self-evident from the nature of babies.

When they sleep, the do so with a peace and softness that comes from how they are protected.

A baby may not 'sleep deep' - in the sense of 'inability to be awoken' (since they wake up crying).... but their sleep is untroubled.