Deliberate exaggeration, which nobody takes literally, used to emphasize a feeling or a situation.
In Othello
If it were now to die, / 'Twere now to be most happy; for I fear
Othello exaggerates when he says that, if death came "now", it would be "the greatest joy". He does not wish to die: the sentence measures the size of his happiness at the reunion, so great that he fears nothing in the future will equal it.