The Foretold Soldier

• WOTC Official Reminder Textofficial rules
  Foretell — Foretell [cost] (During your turn, you may pay and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

• WWizards of the Coast2023-10-13
  Official Ruling
  If a card is a copy of The Foretold Soldier on the battlefield, it can be exiled by the triggered ability and will become foretold. However, it may only be cast this way if it has a foretell cost in exile.
• WWizards of the Coast2023-10-13
  Official Ruling
  Because exiling a card with foretell from your hand is a special action, you can do so any time you have priority during your turn, including in response to spells and abilities. Once you announce you're taking the action, no other player can respond by trying to remove the card from your hand.
• WWizards of the Coast2023-10-13
  Official Ruling
  Regardless of who controlled The Foretold Soldier and exiled it with its triggered ability, only its owner may cast it from exile this way.
• WWizards of the Coast2023-10-13
  Official Ruling
  Casting a foretold card from exile follows the timing rules for that card. If you foretell an instant card, you can cast it as soon as the next player's turn. In most cases, if you foretell a card that isn't an instant (like The Foretold Soldier), you'll have to wait until your next turn to cast it.

Rulings via Scryfall