The prophets never tire of reminding Israel that her election is not a privilege which she may selfishly keep for herself; rather the election is a call to service. It involves a duty to witness among the nations. Israel must be a sign to other nations that Yahweh is both Creator and Liberator. One of the Servant Songs (Isa 49,6) refers to Israel’s mandate to become a light to the nations. Any explanation to this call of Israel comes up with the concept of ‘presence.’ Chosen by God to become the special recipients of His mercy and justice, Israel now has the corresponding duty to live as the people of God among the other nations in order to show them His grace, mercy, justice, and liberating power.
The idea that presence is witness has deep roots in the Old Testament. The prophets continually claimed that by her very act of living out her divine appointment to serve, Israel becomes a sign and bridge for other nations. J. Verkuyl points that the Exodus account and the deuteronomic tradition distinguish between ‘am’ (people) and qahal (the religious community) and expressly mention that already in the desert many individuals had joined the qahal who had not been original members of the ‘am.’ The heathen people, who came along with Israel and dwelt as strangers among God’s people, participated in Israel’s worship. They heard of God’s mighty deeds and joined Israel is songs of praise.
We also have these striking number of individuals who left their heathen origins and by word-and-deed witness were won over to trust and serve the Living God who had shown them mercy. The stories of Melchizedek, Ruth, Job, the people of Nineveh described in the book Jonah, and many others in the Old Testament are windows, as it were, through which we may look out on the vast expanse of people outside the nation of Israel and hear the faint strains of the missionary call to all peoples.
The wisdom literature of the Old Testament is similar in both form and content to both Greek and Egyptian cultures. Without doubt, her own literature served Israel as a means of communicating her beliefs to other nations. Moreover there is no other way of explaining the powerful missionary impact of Judaism during the Diaspora than to affirm that those dispersed Jews from their earliest days had heard and understood their call to witness directly as well as by their presence.
 J. Verkuyl, Contemporary Missiology: An Introduction, (E. Tr. and ed. by D. Cooper), William B. Eerdmans Publishing Company, Michigan, (1978), 94.
 Cf. M. McNamara, “Melchizedek: Gen 14, 17-20 in the Targums, in Rabbinic and Early Christian Literature,” Biblica, Vol. 81, Fasc. 1, Institut Biblique Pontifical, Rome, (2000), 1-31, 27-31.
 Cf. A. Siquans, “Foreignness and Poverty in the Book of Ruth: a Legal Way for a Poor Foreign Woman to Be Integrated into Israel,” JBL, Vol. 128, no. 3, The Society of Biblical Literature, Atlanta, (2009), 443-452, 446-452. M. S. Moore, “Ruth the Moabite and the Blessing of Foreigners,” CBQ, Vol. 60, no. 2, The Heffernan Press Inc., Massachusetts, (2008), 203-217, 210-212. M. S. Smith, “Your People Shall Be My People: Family and Covenant in Ruth 1, 16-17,” CBQ, Vol. 69, no. 2, The Heffernan Press Inc., Massachusetts, (2007), 242-258, 243-247.
 Cf. O. M. Lucas, “Wisdom Literature in the Old Testament,” BB, Vol. IV, no. 4, Bible Bhashyam Trust, Kottayam, (1978), 277-291, 279-28.