The Treasures of Arthur

"You shall receive the gift that your mouth and tongue speak, as far as wind dries, as far as rain wets, as far as sun reaches, as far as sea stretches, as far as the earth is -

except for
my ship
my cloak
Caledfwlch, my sword
Rhongomyniad, my spear
Wyneb Gwrthucher, my shield
Carnwennan, my knife
and Gwenhwyvar, my wife."  

His ship is Prydwen, in which he sailed to the Otherworld (Annwfn) to get the cauldron of rebirth;
His cloak made the wearer invisible;
His sword's name suggests it cuts a breach in battle;
His spear's name means 'spear-striker';
His shield is the face of evening;
His knife's name signifies his fondness for its white haft;
… and his Wife
her name means 'White Enchantress'.

Such things he reserved for himself.
Anything else, had Culhwch named it, his generosity would bestow it.

(from Culhwch and Olwen)