The author of Hebrews heavily depends on the Pentateuch and the Psalms. The Pentateuch, for the most part, offers him material for reflection on redemptive history, and the Psalms provide his Christological material. The great debt the book of Hebrews owes to the Old Testament, however, is not simply a matter of general background and copious quotation, but also extends to fundamental Old Testament ways of thinking which are constantly presupposed and which underlie all passages in the book. The concept of hesed ("faithfulness, kindness, grace, steadfast love, solidarity'' etc) is one of those. According to the Hebrew Scriptures, God revealed God self to God's people at Sinai. This article will deal specifically with the reference to the Sinai revelation as it appears in three Psalms. This discussion will be followed by a short overview of this specific text in the Pentateuch. This article will be concludes by briefly indicating a possible influence these Old Testament texts on the book of Hebrews.