A soldier should know the difference between words and deeds who says this

Line 287; the Guard is the speaker;

Guard remembered that Beowulf is a faithful and exceptional warrior who is there to support them.

A brave hero has to perform heroic actions. Beowulf had killed and the dragon, Grendel and Grendel's mother. All of these are heroic actions which no one else was capable or prepared to take on. The opponents that Beowulf encountered were all beyond individual strength and inclination. Beowulf needed superhuman capabilities to bring down such powerful enemies.