Enjoy something, as in Be sure to have yourself a good nap, or They were having themselves a great time at the fair. The oneself in this colloquial expression adds emphasis to the verb have.
Words nearby have oneself
How to use have oneself in a sentence
The speaker conjures up centuries of collective sagacity, aligning oneself with an eternal, inarguable good.Politicians Only Love Journalists When They're Dead|Luke O’Neil|January 8, 2015|DAILY BEAST
Perhaps there is something too painful about throwing oneself too deep into what went wrong.
When one plays life that way, one in a way awakes creative vital energies in oneself that otherwise are not available.
How many details are needed, after all, before one can say to oneself, “This is what I have lost?”
And so the reaction seems to be to corral oneself off from disagreement.Pew Study: Americans Are Self-Segregating Amid Proliferating Partisan Media|John Avlon|October 21, 2014|DAILY BEAST
The habit of refreshing oneself with a pipe on some elevated spot which commands a fine view, is common to both sexes.
To suddenly discover oneself proficient where failure had been feared increases self esteem and adds to the sum of happiness.
It is good, I believe, to be respectable, but much nobler to respect oneself and utter the voice of God.The Pocket R.L.S.|Robert Louis Stevenson
There is no greater folly than in making oneself disagreeable without any probability of reformation.Beacon Lights of History, Volume I|John Lord
Whether one does this or that, one finds oneself in pretty much the same position at the end.The Daughters of Danaus|Mona Caird