Why did Beowulf's men carry weapons?

Question

In Part VII of Beowulf, Beowulf tells Hrothgar

I shall manage the matter, with the monster of evil,
The giant, decide it. Thee I would therefore
Beg of thy bounty, Bright-Danish chieftain,
Lord of the Scyldings, this single petition:
Not to refuse me, defender of warriors,
Friend-lord of folks, so far have I sought thee,
That I may unaided, my earlmen assisting me,
This brave-mooded war-band, purify Heorot.
I have heard on inquiry, the horrible creature
Since the monster uses no weapons,
From veriest rashness recks not for weapons;
I this do scorn then, so be Higelac gracious,
My liegelord belovèd, lenient of spirit,
To bear a blade or a broad-fashioned target,
A shield to the onset; only with hand-grip
I, too, shall disdain to use any.
The foe I must grapple, fight for my life then

In essence, Beowulf intends to fight the monster, Grendel, without any weapons.

Yet when Grendel does arrive, Beowulf's men are armed:

. . . Many a noble
Of Beowulf brandished his battle-sword old,
Would guard the life of his lord and protector,
The far-famous chieftain, if able to do so;
While waging the warfare, this wist they but little,
Brave battle-thanes, while his body intending
No weapon would harm Grendel; he bore a charmed life.
To slit into slivers, and seeking his spirit:
That the relentless foeman nor finest of weapons
Of all on the earth, nor any of war-bills
Was willing to injure; but weapons of victory
Swords and suchlike he had sworn to dispense with.

Why did Beowulf allow his men to carry weapons, while he himself carried none in order to make it a fair fight?

Answer 1

The first reason is that Beowolf's companions aren't there to fight Grendel, but to lure him into the hall so that Beowolf himself can fight Grendel. Remember that Grendel is a coward (he attacks at night, etc.), and would want to avoid a fight with Beowolf if at all possible.

For example, when Grendel enters the hall, he get's extremely excited when he sees the armed warriors sleeping there, and decides to eat them all up. This will allow Beowolf to surprise him.

Strode he angrily; from the eyes of him glimmered
A lustre unlovely likest to fire.
He beheld in the hall the heroes in numbers,
A circle of kinsmen sleeping together,
He exults over his supposed prey.
A throng of thanemen: then his thoughts were exultant,
He minded to sunder from each of the thanemen
The life from his body

Unfortunately for him, Beowolf is hiding in the crowd, and is able to catch Grendel by surprise:

Nearer he strode then, the stout-hearted warrior
Snatched as he slumbered, seizing with hand-grip,
Forward the foeman foined with his hand;
Caught he quickly the cunning deviser,

The text also tells us that it is necessary for Beowolf to surprise Grendel, because the moment Grendel learns of the strength of Beowolf he wants to flee:

Fearful in spirit, faint-mooded waxed he,
Not off could betake him; death he was pondering,
Would fly to his covert, seek the devils’ assembly:
His calling no more was the same he had followed
Long in his lifetime.

The second reason is that there is a specific symbolic meaning attached to the idea of fighting Grendel without swords and armor. In this case, using swords and/or armor has an element both of pride/hubris (you believe that superior weapons can overcome a supernatural being who uses none) and an element of cowardice (you are afraid to face Grendel on your own without weapons). The use of weapons by Beowolf's companions serves as a contrast between them and Beowolf himself.

(I'm basing my interpretations solely on the text because I don't have time to research how critics or academics interpret this scene. However, I believe that I've done sufficient research to answer the question. All quotations from Beowolf are from the translation cited in the question.)