Pictorial Language Series
The second line of Isa 60:16 reads: "At the breast of kings you will nurse." The mental imagery struck me as being so odd, I just had to investigate. So I brought up other Bible versions. The King James, New American, English Standard, and many others all say “breast of kings.” The New International Version renders it “royal breasts.” The New Living Translation says “breasts of a queen.”
Now I was even more curious. “Does the original Hebrew really refer to “kings” (male)?” So using the same biblehub.com website linked above but switching the “mode” from “parallel” to “interlinear,” I read that indeed the original says “breast of kings.” Now, we all know that males do not lactate, so how is this intended? Backing up to verse five helps shed some light. The wealth of the nations (which back in those days was usually associated with and controlled by its ruler(s)), is said to be given to Israel. In a figurative sense then nursing from the breast of kings is sucking the wealth from them. Was this understood as an assault on the resources of other nations? Not necessarily. 2 Chronicles 2 recounts how King Hiram willingly provided assistance to Solomon. Also, remember that the imagery is of a baby being nursed, so not an adversarial situation.
So now that we’ve solved the issue of correctly understanding this passage, comes the question as to why a few translations decided on such phrasing as “royal breasts” and “breasts of a queen.” You would have to ask them -- It makes no sense to me. Is it possible that because of the Bible versions speaking to “westerners” they may have tried to make it less shocking to English-speaking readers? That is one possibility but it is not a responsible one.