There's no one right answer to this question. And that is a -good thing.-
Because here's what you could do:
Ask the players what skills they -think- could apply to the riddle. And if their suggestion sounds even -halfway- plausible, let them roll the dice for that skill and feel important.
Now here's the clincher... make them require multiple skill rolls--and make it so that each character figures out a different part of the clue.
Suddenly, you have -all- the players contributing to finding the clue that unsticks them. Instead of relying on -the knowing things guy- the party is all involved and -everyone- gets to share in the win.
'Um... well, this part of the riddle mentions Corellon, can I roll Religion?'
'You may! You remember the parable of the Hand of Magic, and recognize the ancient sign for that.'
'Oh oh! Corellon's the god of magic, does that mean Arcana can be involved?'
'You may! As it turns out, mentioning the Hand, you recognize the sigla for the Hand, and the next one for the elbow. While this isn't about magic, there's some of the Ancient Magic Language involved here.'
'Wait, so your clues mention the hand, and the elbow.... I have Athletics, so do I know enough about the body's motions to hazard some sort of connection?'
'You may. Upon discussing with them, you reason the only way for those motions to be involved is by throwing a javelin. They question your expertise, but then you demonstrate for them.'
'Oh hey, throwing a javelin... Corellon, eladrin like to use spears, right? Can I roll Nature to see if this is eladrin make?'
'Absolutely. Turns out, you recognize that the script is written right to left, rather than left to right. Now, normally that wouldn't mean anything, but you -do- remember there's a tribe of eladrin that are all left handed. Perhaps this might relate to them.'
'Wait, left handed eladrin... can I roll History to see if there were any battles in the area?'
'Indeed! As it turns out, there -was- a battle in this area. The Army of the Sinister Sun trampled through here to fight against the orcish hordes. They wrote long sagas and records of the battle, and where various treasures from the battle were hidden after the fight. You all reason this must therefore be a map to find the Javelin of The Sinister Sun! Suddenly it all makes sense!'
'HUZZAH!'