Analysis of information sources in references of the Wikipedia article "Jewish symbolism" in English language version.
... symbols ... used by Jacob, just before his death, in his blessing to his sons in Genesis 49: Reuben is likened to water, Yehuda a lion, Zevulun a ship, Dan a snake and Naphtali a deer. Three other symbols match those used by Moses in his blessings to the tribes, just before his death, in Deuteronomy 33: Joseph is likened to a bull, Benjamin to two hills and Asher to oil or an olive tree. Of the remaining four tribal symbols, some can be found in other ancient Jewish sources. For example, the Midrash says Shimon's symbol was the gates to the city of Shechem (Midrash BaMidbar Rabbah 2:7).
