In this rule

Historical Rules · 7 February 2025

Rule 701.10d

Official source text from the 7 February 2025 Rules release

Permalink

Some spells or abilities may instruct a player to exchange cards in one zone with cards in a different zone (for example, exiled cards and cards in a player’s hand). These spells and abilities work the same as other “exchange” spells and abilities, except they can exchange the cards only if all the cards are owned by the same player, and they can exchange the cards even if one zone is empty.

Find this number in the current Rules