The aim is to discuss the biblical-theological reflection on the social trilogy foreign, orphan and widow in Dt. In this biblical book are six explicit references to this trilogy: 10, 12-22, 14, 28-29, 16, 9-12, 24, 17-21, 26, 12-15, 27, 11-26. The presence of these categories points out the significant set of legal rules in Ancient Israel. The laws were made in order to defend the rights of socially vulnerable groups, in a certain political and social context, as you can find out from the clash with the design of the belligerent Assyrian Empire (722 BC) and later, with the experience of religious post-exile community (537 BC), after clashes with the troops of Babylon. The narratives, beyond this point, show the level of intimacy involving YHWH. In a social context, completely adverse to the Jewish communities in the first two centuries of our area, the Mishná points out the wise Pharisees efforts to put into practice the precepts always present of the Torah. To read the two literary worlds - Dt and Mishná - from the perspective of socially vulnerable groups, is a challenge to understand the significant value that the Jewish tradition has had about the understanding of the concept Word of YHWH.