"Thus saith the Lord, the God of Israel; I made a covenant with your fathers in the day that I brought them forth out of the land of Egypt, out of the house of bondmen, saying, At the end of seven years let ye go every man his brother an Hebrew, which hath been sold unto thee; and when he hath served thee six years, thou shalt let him go free." - Jer. 34:13, 14,
F.R.A. Glover: Another footfall by which the path of the prophet Jeremiah is to be tracked in his sojourn in Ireland, is to be seen in the Law of Release of the Slave after seven years of bondage: a law in common acknowledgment in Ireland even down to the days of St. Patrick. That illustrious personage having claimed freedom, from his bondage after seven years of service, according to it, from the master, to whom he had been sold by the pirates who bad seized him from his paternal home, on a raid into Brittany; this master refusing like the Jews in the time of Jeremiah, to fulfil the will of God in this wise, the saint was compelled to have recourse to gold to obtain that which the tyrant refused to accord to right and law. But so the fact comes out: viz., that the law, more Hebraico, s the Annalist intimates, en passant, set up by the "Prophet to the Nations," if by him, had abided in full repute, for 800 years, the Law of the Land; a law which, we may well believe, the Prophet would have bad it much in his mind to insist upon to his new people, in the recollection of the woe which its neglect and denial had wrought upon that elect nation, of whose small remnant he had been, partly on this very account (Jer. 34), the leader from an earthly paradise to the wild wastes of Crioch Fuiniab, "the ends of the earth," - Emerald Isle though they be!
It is said in some of the Lives of St. Patrick, that there was a law in Ireland, according to which slaves should become free in the seventh year; and that it was under this law he gained his liberty. The same writers add, that this was conformable to the practice of the Hebrews, more Hebraeorum, (Lev. 25:40). See on this point Dr. Lani, chap iv. From Moore's Ireland, vol. i. p. 219, note.
From: "England, the Remnant of Judah, and the Israel of Ephraim", written by F.R.A. Glover, M.A., Chaplain to the Consulate at Cologne. Published by Rivingtons, London, 1861. Based on research commenced in 1844.