Without seeing what position you have in mind.
White has played Kh1.
1) To rush up the f-pawn and not be surprised by any mid-combo checks.
2) To allow Rg1 to use the g-pawn as a bayonet.
3) To allow Rg1 because g2 is going to need some serious defending.
4) Possible spoiling check coming with Ne2+ or Nf3+ or Nh3+
5) Every piece is placed on it's best square moving a piece or pawn would be bad.
6) hedonist is White he wants to hop the Knight back to g1 to come out at h3. Thread 145493
7) White cannot think of anything else to do.
8) The computer says it give White a 0.02+
9) Black has just played Kh8. (distant opposition)
10) Mozart Carlsen played it one of his games.
11) It's theory.
12) White is in Zuggers.