Sam did not even advance that much when something unexpected happened. Actually at the time not far from that place he could see some people waiting for him. Actually he wasn't sure at first if those people were waiting for him or not but those people just kept looking in his direction so naturally it looked like they were waiting for him and with that he really became curious.
First of all those people were elf. So naturally he knows that he did not have any type of conversation with elves. Even though he previously rescued some of them from the Toron kingdom, then previously those Warriors already said thanks and expressed their gratitude so he became sure that those people weren't waiting for him because of this. So the question was why were they waiting for him?