The six lines given make up three different poems. From The Fairies, by Irish poet William Allingham (1850):
Up the airy mountain, down the rushy glen
We dare not go a-hunting for fear of little men
From a traditional Cornish prayer:
From ghoulies and ghosties and long-leggety beasties
and things that go bump in the night
Good Lord deliver us
And finally from a traditional school girls’ skipping rhyme:
My mother said I never should
Play with the fairies in the wood
If I did, she would say
You naughty girl to disobey
Your hair won’t grow, your shoes won’t shine
You naughty little girl, you shan’t be mine!