'Childless' in the Bible

"Teacher," they said, "Moses enjoined, 'If a man die childless, his brother shall marry his widow, and raise up a family for him.'

Now we had among us seven brothers. The eldest of them married, but died childless, leaving his wife to his brother.

And so did the rest of the seven, all dying childless. Finally the woman also died.

Now there were seven brothers. The first of them took a wife and died childless.

But he gave him no inheritance in it, no, not a single square yard of ground. And yet He promised to bestow the land as a permanent possession on him and his posterity after him--and promised this at a time when Abraham was childless.