Ashaya's Enduring Bond is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.) Discover X, where X is the amount of mana spent to cast this spell. (Exile cards from the top of your library until you exile a nonland card with that mana value or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.) Ashaya's Enduring Bond can be your commander.