I will give my love an apple

I will give my love an apple without e'er a core
I will give my love a house without e'er a door
I will give my love a palace wherein he may be
And he may unlock it without any key

My head is the apple without e'er a core
My mind is the house without e'er a door
My heart is the palace wherein he may be
And he may unlock it without any key