Before Gus and Gyirab knives were produced, King Gesar, the longest epic in the world, already had segments praising Tibetan knives. For example, the Battle Between the Hor and Ling States, part of the epic, lauds the knives in this way:

Don’t you recognize this treasure knife in my hand?
It was cast in the auspicious state of the Han area.
Nine brother blacksmiths,
Cast it with smelted iron when stars hung bright in the sky.
Called “Sharp Stars,”
Such knives were forged out of iron and copper pieces,
Which were heated and dipped in the clod blood of crocodiles.
Where the Han people live,
These knives are called “Demon Suppressers”.
When they are put into rivers and lakes,
It is called “Turning the Tide”.
When they are used by servants,
They are called”100 Pine Trees Choppers”.
When they are used by maids,
They are called” 1,000 Cakes Makers”.
When they are brought to the Ling State,
They are respectably mentioned as” Yasgarchon”.
Each is inlaid with four gold nails,
Resembling twinkling stars in the dark night sky.
Adornments on the knife handle are like snow-covered mountain peks,
And the tassel adorning the knife handle is like a hoop used to tame fierce cows.
The knife’s hand guard impresses people like the weak conquering the strong.
The knife’s sheath has patterns showing shining stars.
The knife’s sheath top looks like the Yellow River winding its way around a
Snowy Mountain.
The knife’s sheath hoops are like pendulums dangling on the bosoms of girls.
The front of the knife sheath is like the sun shining over the East Mountain.
The back of the knife sheath is like six tribes meeting for peace talks.
The knife ridge is like heavy snow over mountain valleys.
The knife blade resembles a crescent moon.
The knife’s top is like a flame licking the blue sky.
A treasure knife like this that sends out fire and wind,
Can be used to defeat the fiercest enemy.