The most common and most likely answer to this crossword clue is the 7 letter word PROVERB
I've seen this crossword clue in The Times
P
R
O
V
E
R
B
More clues leading to the result PROVERB
- Saw dog restrained by lead
- Saw run completed, breaking personal best
- Saw dog in pub — not acceptable
- Wise words show real brains, primarily
- Saw rambler in empty pub
- Saw person wandering in empty pub
- Put lead around dog? Let sleeping dogs lie, perhaps
- Saw British returning after Test
- Demonstrate right book shows a bit of wisdom
- Saw wanderer is in lead
Buddy explains!

The straight part
We know that "Let sleeping dogs lie, perhaps" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case let sleeping dogs lie, perhaps = proverb.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does PROVERB mean?
PROVERB noun- A phrase expressing a basic truth which may be applied to common situations.
- A striking or paradoxical assertion; an obscure saying; an enigma; a parable.
- A familiar illustration; a subject of contemptuous reference.
- A drama exemplifying a proverb.
- To write or utter proverbs.
- To name in, or as, a proverb.
- To provide with a proverb.