There are two traditions concerning Abraham’s blessing for all the families of the earth. One interpretation understands the ‘blessing’ in a reflexive sense while the other takes it as passive. The Hebrew verb is the niphal. The Hebrew niphal usually has a passive sense, although it can also bear a reflexive meaning. The version that takes the niphal as a reflexive sees Abraham to be a paradigm of blessing. The families of earth may use his name for blessing and may wish to be blessed as he is. But it is not said explicitly that blessing comes to them through Abraham (the sense would be close to that expressed in Gen 48,20; 22,18). The version that takes the niphal as passive considers Abraham to be a source or agent of blessing to all families of earth. The promise is repeated to Abraham in Genesis 18,18 and to Jacob in Genesis 28,14, both are in the niphal. But it also occurs in the hitpael when repeated to Abraham in Genesis 22,18 and to Isaac in Genesis 26,4. Westermann argues that, as far as the promise is concerned the niphal and the hitpael have the same meaning and that both have a universal import. God’s promise to Abraham is not limited to him and his posterity, but reaches its goal only when it includes all the families of the earth. This interpretation carries more weight with the growth of universalism after the exile. It means that is some way blessing comes to others through Abraham.
 Cf. A. Retif and P. Lamarche, The Salvation of the Gentiles and the Prophets, Helicon, Dublin, (1966), 21.
 J. C. Okoye, Israel and the Nations: A Mission Theology of the Old Testament, Orbis Books, Maryknoll, New York, (2006), 47. In Genesis 18,18 Yahweh invokes the fact that “in you all nations on earth shall be blessed” to reveal to Abraham the divine project of the punishment of Sodom and Gomorrah. Thereupon, Abraham exercised the office of intercession and succeeded in getting a reprieve for Sodom if only ten people were found righteous in that city.