Grizel, but--yes, it must have been that, and it is hard on me." He was in misery, and these words leaped out.

They meant only that it was hard on him if Elspeth had to be told of his engagement in the hour of her dejection.

He did not mean to hurt Grizel to the quick.
However terrible the loss of his freedom might be to the man who could not love, he always intended to be true to her.

But she gave the words a deeper meaning.
She stood so still she seemed to be pondering, and at last she said quietly, as if they had been discussing some problem outside themselves: "Yes, I think it must have been that." She looked long at him.

"It is very hard on you," she said.
"I feel sure it was that," she went on; and now her figure was erect, and again it broke, and sometimes there was a noble scorn in her voice, but more often there was only pitiful humility.