"The basis of the family (in ancient Israel) is marriage, understood as a covenant between the husband and wife. ... Although some texts imply a monogamous relationship, at least in earlier periods polygamy was an accepted practice, enlarging the scope of the family. And in a broader sense, the extended family included other relatives (grandparents, grandchildren, siblings), as well as slaves, servants, and resident foreigners. In the extended family, the authority of the father was the strongest cohesive force. He arranged marriages for his children, generally within the clan. ... Yet in the teachings of Jesus, his followers must give no more than second place to even the closest family ties: the true family of Jesus are those who do his father's will." - The Oxford Companion to the Bible, pp. 223f.