Temporal Tribulation 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

Exile two target permanents you control. Return those cards to the battlefield under their owner's control at the beginning of the next end step. Flashback (You may cast this card from your graveyard for its flashback cost. Then exile it.)