It is stylistic. It is poetry. Grammar rules are not very important in that medium.
Is the absence of article before the words sand and sky used for stylistic purposes? Or is it just a grammar mistake?
Don’t write your name on sand, waves will wash it away.
Don’t write your name in sky,Wind may blow it away.
Write you name in hearts of people you come in touch with.
That’s where it will stay.
If I were a native speaker of English, I would never shut up. :-)
That should be "Is the absence of an article ...?" or "Is the absence of the article ...?"
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.
Or 'Is the absence of articles...?'