The purpose of citing textual evidence in a literary analysis essay is to...
to support the argument made in the thesis statement.
It's always good to cite textual evidence, especially in a literary analysis essay because it supports the argument. To give a proper and valid argument you need evidence to back it up what you want to say. Otherwise, your argument can, possibly, not be taken seriously by readers.
The purpose of citing textual evidence in a literary analysis essay is to let the readers know that the particular text is cited from a different source and see the end part of the paper for the full source of citation and ideas that you applied in your essay.
