The sons of Shelah the son of Judah were, Er the father of Lecah, and Laadah the father of Mareshah, and the families of the house of them that wrought fine linen, of the house of Ashbea,
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 occupation of their forefathers was a compulsory obligation; whereas in Israel, as in many parts of Asia to this day, it was optional, though common.