great things of ... law - (Deu 4:6, Deu 4:8; Psa 19:8; Psa 119:18, Psa 119:72; Psa 147:19, Psa 147:20). Maurer not so well translates, “the many things of My law.”
my law - as opposed to their inventions. This reference of Hosea to the Pentateuch alone is against the theory that some earlier written prophecies have not come down to us.
strange thing - as if a thing with which they had nothing to do.