In plain words
If metals such as copper and brass are mixed into it, its price falls. Not only that. It loses its lustre. If still more metals are mixed in, in the end the gold has no value at all. Our heart is a Golden Temple. It is Hiraṇyagarbha. In that gold there must be no change at all. It must go on shining always. Only if it stays that way is it good. Instead, you must not mix in this one's and that one's and make it impure. Share Prema. Live in unity, in purity.