Green’s Dictionary of Slang

(Irish/Scots) one’s soul.

1831		Perthshire Advertiser 5 Oct. 2/2: They laid Rice’s head on a block and threatened [...] not leave a priest’s share in him — a well known phrase for putting a fellow-being to death.
1841		Waterford Chron. 24 July 2/3: He [...] expressed his determination to leave but the ‘Priest’sa share of life in them;’ an expressive saying used to the beating of a person ‘within an inch of his life’.
1861		Wexford Indep. 6 July 3/1: Defendant ran after her, and kilt her again, telling her he would not leave the Priest’s share in her.
1876		Cork Constitution 15 July 3/3: She found her daughter-in-law was killed by the falling of the chimney. She asked him to go up and see was ‘the priest’s share’ in her.
1910		P.W. Joyce Eng. As We Speak It In Ireland (1979) 307: A mother will say to a refractory child:— ‘I’ll knock the priest’s share out of you.’.