Abraham, Isaac and Jacob do not signify ideas, principles or abstract values.

A.J Heschel, Man's Quest For God, Aurora Press, p. 88. Bear with me on this one. There is a very basic idea here of Heschel's in regard to the "Jewish - Biblical outlook" on the world. Either subsequent quotes in the upcoming days or your own looking into Heschel's exposition "ibid", or both will clarify the idea...or not