1
general::
Phrase(s): let someone, something, or some creature be
Go to leave someone, something, or some creature alone.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Leave undisturbed, refrain from interfering with. For example, Stop fussing with the tablecloth; let it be, or, as A.E. Housman put it in A Shropshire Lad (1896): "Will you never let me be?" [Second half of 1100s] Also see LEAVE SOMEONE ALONE; LEAVE SOMEONE IN PEACE.
American Heritage Idioms