A dictionary of Proverbs (Oxford Paperback Reference)

If the SKY falls we shall catch larks
‘In ridicule of those who talk of doing many things, if certain other things, not likely, were to happen’: Fielding, Proverbs of all Nations (1824) 22.

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  c 1445 Peter Idleys Instructions to his Son (1935) I. 178 We shall kacche many larkis whan heuene doith falle. 1546 J. HEYWOOD Dialogue of Proverbs I. iv. B1^V When the sky falth we shalhaue larks. 1670 J. RAY English Proverbs 143 If the sky falls we shall catch larks. 1721 J. KELLY Scottish Proverbs 343 What if the Lift [sky] fall, you may gather Laverocks [larks]. 1914 G. B. SHAW Misalliance p. xxx. I cannot be put off by the news that our system would be perfect if it were worked by angels.. just as I do not admit that if the sky fell we should all catch larks. 1950 C. S. LEWIS in Month Oct. 234 If.. the total content of time were spread out before me.. I could do what the Historicist says he is doing. .. Yes; and if the sky fell we should all catch larks. ■ possibility and impossibility
  

sky see also RED sky at night, shepherd’s delight; WINTER never rots in the sky.
slave see BETTER be an old man’s darling, than a young man’s slave.
sleep see one HOUR’S sleep before midnight is worth two after; SIX hours’ sleep for a man, seven for a woman, and eight for a fool.
Let SLEEPING dogs lie
Cf. early 14th-cent. Fr. n’esveillez pas lou chien qui dort, wake not the sleeping dog.

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  с 1385 CHAUCER Troilus & Criseyde III. 764 It is nought good a slepyng hound to wake. 1546 J. HEYWOOD Dialogue of Proverbs I. x. D1^V It is euill wakyng of a slepyng dog. 1681 S. COLVIL Whigs’ Supplication II. 27 It’s best To let a sleeping mastiff rest. 1824 SCOTT Redgauntlet I. xi. Take my advice, and speer [ask] as little about him as he does about you. Best to let sleeping dogs lie. 1976 T. SHARPE Wilt xx. He would be better off sticking to indifference and undisclosed affection. ‘Let sleeping dogs lie,’ he muttered. 1996 M. MACDONALD Death’s Autograph ix. 98 ‘They don’t have to prove it! He’s dead. It can’t do him any harm now.’ She said distinctly, ‘Let sleeping dogs lie, then.’ «action and inaction; busybodies