'I reckon every man born of woman has his log to shift in the world--if so be you're hintin' at any o' Frankie's doings. He never hit beyond reason or without reason,' said Simon.
'I never said a word against Frankie,' Puck retorted, with a wink at the children. 'An' if I did, do it lie in your mouth to contest my say-so, seeing how you--'
'Why don't it lie in my mouth, seeing I was the first which knowed Frankie for all he was?' The burly sack-clad man puffed down at cool little Puck.
This is from “Simple Simon” from “Rewards and Fairies” by Kipling.
http://www.telelib.com/authors/K/KiplingRudyard/prose/RewardsFaries/simplesimon.html
I do not understand what “do it lie in your mouth” mean.
I am glad if somebody teach me.