Ben was surprised and touched by Al's offer, and he impulsively hugged Al, patting him on the back three times like he'd seen Jamie do. Hopefully he hadn't over stepped, but Ben was a physically demonstrable person, and Al's offer had really touched him.
"Thank you," he said/wrote. "That means a lot that you'd offer." There was something different about the Al who was here, and the Al that he'd lived with, and he liked the difference. It made Al a little more approachable. He wondered if it was Professor Snape's influence, or the siege. Probably both.
"I'll talk to you soon. Let me know how your healing progresses." His dad would have wanted to stay informed on that, and Ben did as well.