“Make two cherubim of gold—make them of hammered work.”
– Exodus 25:18, JPS 1985 Tanach
The keruvim (angels) were made out of gold, that had been hammered out from the ark cover, all from one piece of gold. This may symbolize the harmony between the Shechinah (G-d’s Presence) that rested between the keruvim on the ark-cover, and His angels. “Upon the firmament that was over the head of the cherubim, there appeared above them as it were a sapphire stone, as the appearance of the likeness of a throne” (Ezekiel 10:1, JPS 1917 Tanach). Additionally, from the perspective of the sefirotic tree of life, one wonders whether the unity may have to do with keter, chochmah, and binah. Inasmuch that I am not nearly as cognizant of the Jewish mystical treatise, the Zohar, as I would like to be, this is only a speculation on my part.
In any case, these golden keruvim (angels) are a topic of fascination for the sages, if it is feasible to judge their interest with keruvim based on the extended commentary found in certain Jewish sources. For example, R’Bachya comments that one reason for the golden cherubim being constructed as part of the ark-cover, is to remind of the existence of G-d’s angels, whom He created to enact miracles on earth. They may serve as a bridge between the heavenly realms, and the earthly realm, where they carry out the missions given to them by H’Shem. Additionally, “we are required to believe in the existence of angels” (R’ Bachya, commentary on Exodus 25:18, as found at sefaria.org).