Quote 1
"When you say 'master of Death' –," said Ron.
"Master," said Xenophilius, waving an airy hand. "Conqueror. Vanquisher. Whatever term you prefer." (21.37)
This idea of the "master of Death" follows upon the notion we saw alluded to on Lily and James's gravestone – the idea that one might somehow trump Death or have supremacy over it. And it's fitting that Harry, the heir of the Peverell brothers, should assume that rightful title in the end.
Quote 2
"[Dumbledore] knew what he was doing when he gave me the Deluminator, didn't he? He – well," Ron's ears turned bright red and he became engrossed in a tuft of grass at his feet, which he prodded with his toe, "he must've known I'd run out on you."
"No," Harry corrected him. "He must've always known you'd always want to come back." (20.9)
Harry gently turns around the shame that Ron feels about leaving– as Dumbledore knew, Ron's loyalty is undying, and even though he seemed to give up, he'll always want to come back to his friends.