Jamieson, Fausset & Brown, on 1Chr 4:21

“The sons of Sela the son of Juda: Her the father of Lecha, and Laada the father of Maresa, and the families of the house of them that wrought fine linen in the House of oath.”

“POSTERITY OF SHELAH. (Ch1 4:21-23) Laadah . . . the father . . . of the house of them that wrought fine linen--Here, again, is another incidental evidence that in very early times certain trades were followed by particular families among the Hebrews, apparently in hereditary succession. Their knowledge of the art of linen manufacture had been, most probably, acquired in Egypt, where the duty of bringing up families to the occupations of their forefathers was a compulsory obligation, whereas in Israel, as in many parts of Asia to this day, it was optional, though common.”

Imported from an open dataset — not yet checked against the printed edition.