Wall was ejected from the Wizards' game against the Golden State Warriors after picking up a second technical for jawing at Thompson during the third quarter. Wall was not happy that Thompson fouled him hard on a fast break and later shoulder-checked him after the whistle. He went right at Thompson following the second incident and began shouting in his face, drawing a technical for his actions. Since it was Wall's second technical foul of the game, he was thrown out.
As you can see from this Vine that Truth About It captured, it looked like Wall was telling Thompson, "Go to the basket, and I'll knock your a** out." Or, he was just saying "GO TO THE BASKET." It's tough to tell.
Wall's frustration is understandable, in the sense that he was hit hard, is human and will react emotionally. I can't blame him for being upset. But given that he already had a technical from earlier in the game, he has to understand that hanging back is the better approach. Let Randy Wittman pick up the technical on your behalf rather than trying to send a message to Thompson yourself.