🔼The name Chaldeans in the Bible
But no! says Jones' Dictionary of Old Testament Proper Names. The Chaldeans were mentioned long before Chesed was born. The Chaldeans are first mentioned in Genesis 11:28, in the compound Ur of the Chaldeans, the birthplace of Abram (spelled Χαλδαιος in the Greek New Testament; Acts 7:4), and Chesed is the fourth son of Nahor, the brother of Abram (Genesis 22:22; the name Chesed is spelled Χαζαδ, Chazed, in the Septuagint).
It is, however, quite possible that the Chaldeans are implied to have descended from Chesed, and that the name was applied to them and to Ur in retrospect. A similar retrospection occurs in Bethel, where Abraham dwelled long before his grandson Jacob saw his famous ladder and renamed the place from Luz to Bethel (Genesis 12:8 & 28:19). Moreover, in several instances, our name is spelled not as the regular plural form of an ethonym drawn from the name Chesed (כשדים, Chesedans, or "those of Chesed"), but rather as a forced form that accentuates the plurality of an autonomous quality that in turn derived from Chesed: כשדיים (Chesedeans, of "Chesedly ones", 2 Chronicles 36:17, Ezekiel 23:14). Note also that the name כשדים is sometimes used for the country rather than the people (Jeremiah 50:10, Ezekiel 23:15).
The Oxford Companion to the Bible states, "The Chaldeans were a group of five tribes who became dominant in Babylonia during the late sixth century BCE. They are not mentioned by name in any source before the ninth century, which makes the Biblical phrase "Ur of the Chaldeans" relatively late".
But Jones is right in that the Bible mentions nowhere that the Chaldeans descended from Abraham's nephew Chesed, and that would seem like a good point to notice. It's probably much more likely that Chesed was named after the people that his family once belonged to and left behind.
The Chaldeans and the Babylonians are not to be considered the same people but in the Bible the two names obviously overlap somewhat. The prophet Ezra speaks of Nebuchadnezzar the Chaldean (5:12), while usually he's called the king of Babylon (Ezra 2:1). And Isaiah calls Babylon "the beauty of kingdoms, the glory of the Chaldean's pride" (13:19). BDB Theological Dictionary additionally notes that the Chaldeans were considered a learned class in Babylon, skilled in interpretations. Hence, when king Nebuchadnezzar wanted his troubled dreams explained, he summoned the magicians, the conjurers, the sorcerers and the Chaldeans.
The Chaldeans apparently considered themselves clairvoyant enough to expose the deeper meanings of any nocturnal image but were unable to probe the kings head for the actual dream. The king, furious, announced that he would have all the wise men of the kingdom executed. The Chaldeans hadn't seen that coming either.
Their gloomy future took a turn for sunnier days when Daniel, a young captive from Judah, requested an audience with the king and was able to tell the dream and satisfactorily interpret it. King Nebuchadnezzar was so grateful that he subsequently made Daniel the boss over all the wise men in the realm, including the Chaldeans. What wise things Daniel had them do is not told, but perhaps they had a knack for predicting what would be for dinner (Daniel 2).