This idea appears over and over again, and I failed to find where does it come from. I know that the sefirot are matched by the Ushpizin by the Arizal, Abraham stands for chesed, Yitzchak for gevurah/din, and Yaakov for emet/tiferet, but I think only tiferet is appearing in Zohar.
Where does the notion that Yaakov is "emet" come from? Especially in the light of narratives in recent parashiyot in Chumash (which was addressed by a number of later meforshim)?
(I know Micah 7:20 says תתן אמת ליעקב, but on a pshat level, it has nothing to do with being "epitome of truth", or "perfecting middat haemet to the utmost level". Rather, is a request that Hashem should grant truth for the offspring of Yaakov, the Jewish nation.)