Eliezer is a wise servant. He foresees a problem before he sets out. In Targum Pseudo-Jonathan on Genesis 24:5, the Aramaic renders his careful question: suppose the woman may not be willing to come after me to this land; shall I, returning, make thy son return to the land from whence thou camest?
This is the exact right question. Abraham is sending his servant nearly 500 miles northeast to Paddan-Aram, to his brother Nachor's household. What if Rebecca — though the servant does not yet know her name — refuses to travel? Should Isaac come to her instead?
The Aramaic phrase ashev atavet — shall I make him return — is legally precise. Eliezer wants the contingency written into his mandate before he takes the oath. A good servant does not improvise on a mission this sacred.
In the verse that follows (Genesis 24:6), Abraham's answer will be absolute: Beware that thou bring not my son thither again. Isaac, who has been offered on Moriah, cannot leave the Land of Israel. The rabbinic tradition (Bereshit Rabbah 59:9) explains that because he was consecrated as a sacrifice, he became permanently sanctified to the land.
The Maggidim read Eliezer's question as a model of responsible service. The takeaway: before you accept a mission, ask about the exceptions. The loyal worker does not guess at the master's intent — he brings the difficult question to the surface, and waits for the answer.