If you return four or more nontoken permanents, the permanent card you put onto the battlefield may be one of the cards returned to your hand this way.

Any abilities that trigger as the nonland permanents are returned are put onto the stack at the same time as any abilities that trigger as the permanent card is put onto the battlefield (if applicable).

If a permanent would be returned to your hand but ends up in another zone (most likely because an effect exiled it instead or because it's a player's commander in the Commander variant) Flood of Tears counts it when determining whether four or more of your nontoken permanents were returned.