A dictionary of Proverbs (Oxford Paperback Reference)

1609 S. HARWARD MS (Trinity College, Cambridge) 121 Tales lose nothing by the cariadge. 1721 J. KELLY Scottish Proverbs 44 A Tale never loses in the telling. Fame or Report.. commonly receives an Addition as it goes from hand to Hand. 1907 Spectator 16 Nov. 773 A story never loses in the telling in the mouth of an Egyptian. 1954 L. P. HARTLEY White Wand 15 No doubt Antonio was telling the story to his fellow­gondoliers and it would lose nothing in the telling. 1979 M. STEWART Last Enchantment 19 Like all strange tales, it will grow with the telling. ■ rumour

tale see also DEAD men tell no tales.
Never tell TALES out of school
The phrase to tell tales out of school is also used.

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  1530 W. TYNDALE Practice of Prelates B1V So that what cometh once in may never out for feare of tellinge tales out of scole. 1616 J. WITHALS Dict. (rev. ed.) 573 You must not tel tales out of the Tauerne. 1721 J. KELLY Scottish Proverbs 303 Tell no School Tales. Do not blab abroad what is said in drink, or among Companions. 1876 I. BANKS Manchester Man I. xv. All attempts to make known school troubles and grievances were met with ‘Never tell tales out of school’. 1963 A. CHRISTIE Clocks xxiv. ‘Well—.’.. ‘I understand. Mustn’t tell tales out of school.’ ■ malice
  

TALK is cheap
Cf. c 1600 A. MUNDAY et al. Sir T. More (1911) 23 Woords are but wordes, and payes not what men owe; 1639 CHAPMAN & SHIRLEY Ball v. i. You may heare talke; but give me the man That has measur’d ’em: talkes but talke.

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  1668 R. B. Adagia Scotica 47 Seying goes good cheap. 1843 T. C. HALIBURTON Attache I. ii. Talk is cheap, it don’t cost nothin’ but breath. 1929 K. C. STRAHAN
  

Footprints i. Talk’s cheap. You could never make me believe that. 2002 Washington Times 16 Mar. F15 (Herb & Jamaal comic strip)’Talk is cheap.. because the supply always exceeds the demand.’ "boasting; words and deeds