Thou shalt fear the Lord thy God
Which includes the whole worship of him, external and internal:
him shalt thou serve;
heartily and sincerely, according to his revealed will, and him only:
and to him shall thou cleave;
and not turn aside to follow other gods, and worship them:
and swear by his name;
and his only, whenever it is necessary to take an oath, which should not be done rashly or on trivial accounts; and never by any creature, but by the living God; see ( Deuteronomy 6:13 ) .