Dora Bas Rivka Silver O'H
G-d told Hoshea to marry a second woman, in addition to the first wife. This woman will be beloved, but she'll have a history of adultery. This is like the situation with G-d and Israel; He loves them, but they have a history of infidelity. Hoshea betrothed this woman (or G-d betrothed Israel) with a dowry of 15 pieces of silver and a measure of barley. (The dowry symbolizes the 15th day of Nisan, when G-d redeemed the Jews from Egypt, the silver shekels and the omer of barley. There are other interpretations.) The bride was cautioned to not cheat on her husband.
The Jews would be a long period in exile with no king of the Davidic dynasty, nor sacrifices in the Temple. Afterwards, they would return and seek G-d and His anointed one. They will repent out of awe of G-d and can expect to receive His goodness.