Parshat Mishpatim 5786 - "לה׳ לבדו"

This week’s Parsha is פרשת משפטים, where, following מתן תורה, the Torah turns to legal matters and lays out a multitude of prohibitions. In the midst of these laws, the Torah states: “זבח לאלהים יחרם בלתי לה׳ לבדו - One who sacrifices to gods shall be destroyed - to HaShem alone!” This verse is incredibly difficult. We were already commanded regarding the איסור of עבודה זרה; in fact, it’s the second commandment in the עשרה דברות! Why, then, does HaShem repeat it here - what is He adding? Furthermore, the Torah later states that the punishment for this עבירה is סקילה. If so, why does this פסוק use the term יחרם, rather than language more consistent with other עבירות punishable by stoning? Lastly, the ending of the פסוק seems superfluous: לה׳ לבדו - To HaShem alone, is already evident! Why, then, does the Torah include these two words - what do they come to teach?