Just knowing.
Dwalin and Balin
I DO NOT OWN THE HOBBIT
Dwalin and Balin
If you looked at Dwalin and Balin together you would never see the resemblance. You would never know they were brothers. They hardly spoke to each other. They hardly looked at each other. They never stood together, ate together or trained together. And when they did trade words; it was usually some sort of hidden insult or a call to arms. There was nothing really that singled them out as being brothers.
Yet if you asked Dwalin what Balin was wearing, he could tell you right down to the colour of his socks.
If you asked Balin what arrangement of weapons Dwalin had today, he could tell you right down the however amount of hidden knives that Dwalin had on his person and he was always right.
If you asked Dwalin where Balin was, he didn't need to turn to find him. He would just point and Balin would be there.
If you asked Balin where Dwalin was, he would give you precise directions and tell you why he was standing in whatever position he was standing in, without so much as a glance in his direction.
Because to Balin and Dwalin, being brothers didn't mean always being together. They knew that they had each other's back. They know that they loved each other. They knew that the other cared. And if you asked how did they know.
They would each reply, "I just do."