‘Adah bore Jabal, he was the father of those who dwell in tents and have domesticated animals.'
This is looking from the Cainite point of view. It may suggest that he invented the tent as opposed to more primitive shelters, but more probably that under him domestication of animals by the nomads of the line of Cain now began for the first time. Possibly, in view of Cain's actions, the domestication of animals had been taboo, but now at last they feel it is time the result of the curse was over.