The mighty men were soldiers of heroic proportions. They were strong, skilled, and courageous enough to accomplish things that seem nearly fantastical. These men were the strongest supporters of David, both politically and militarily.
The parallel passage to this one is 2 Samuel 23:8–39, with some alterations. The list of mighty men is divided into “the three” and “the thirty”, though two of the “three” have been condensed into one account here, and the “thirty” is closer to forty-five. The “three” were considered the mightiest among the mighty. Their deeds were the most renowned, the most decisive victories against the longest of odds. And it is clear that the Lord is the one who caused them to have those victories.
The story about the three getting the water from a well in Bethlehem (David’s home town, remember) is very strange to me. I don’t know quite what to make of it. On one hand, it’s a really stupid flex to go past enemy lines to get something very unimportant, just because your king says he wishes someone would get it for him. On the other hand, it’s an extremely impressive flex that they managed to pull it off. I suppose that’s why David decided to sacrifice the water as a drink offering to the Lord. He realized he wasn’t actually worthy of the devotion these three muscle-brains had for him, but the One who helped fulfill their mission was worthy of it. And maybe he watched what he said around them more often after that.
(Really off topic, but this episode reads almost like a video game side quest, or a slapstick comedy. I’m sure they used a water skin, but I can’t help but imagine these three guys running with a bucket, trying not to spill while being chased by Philistines. Hijinks ensue and the bucket is dropped or broken, but they manage to keep the dipper full of water to present it to David.)
We are also told about a couple of men who sound basically as impressive as the three, but who didn’t make the cut to be counted with them. It seems like we get their stories in order to make us more impressed with the three, because our imaginations will fill in the details since the three must be more impressive than these.
After these two, the rest of the mighty men are named. Many are from various parts of Judah, which makes sense as David’s tribe. But there are some from Benjamin, Saul’s tribe, and also some non Israelites as well. The most famous of these is Uriah the Hittite. He was Bathsheba’s husband when David saw her bathing on the roof. The passage in 2 Samuel ends with Uriah’s name as an emphasis that David had many mighty men and did mighty deeds himself, but he was still a sinner. In fact, 2 Samuel continues with another of David’s major sins, so that record is definitely making sure the reader understands how flawed David was. The Chronicler adds some more of David’s supporters after Uriah, and doesn’t address David’s adultery anywhere. He is trying to get the people to trust in the Davidic line as the valid ruler of their nation, which would be hard if he reminded them of the sins he committed.
With Your strength we can defeat lions, strong enemies, and also the sins that entangle us.