Hosea - Chapter 1
A Strange Request
G-d spoke to Hoshea, the son of Beiri. He lived during the reigns of Uziah, Yosam, Achaz and Hezekiah in Judah; Yeravam the son of Yoash (Jeroboam II) was the concurrent king in Israel.
At the beginning of his prophecy, G-d told Hoshea to marry a prostitute and have children with her, the result being that others will question their paternity. (The reason for this is that adultery is the usual metaphor for idolatry in the relationship between G-d and Israel. G-d was putting Hoshea in a position through which he would understand G-d's "predicament" with Israel.)
So, Hoshea married a prostitute named Gomer and had three children with her, two sons and a daughter. G-d instructed Hoshea to name the first son Yizrel (Jezreel), a reference to the location where the family of Ahab was killed by Yehu in II Kings 10. (Ahab and Yehu were both kings of the northern kingdom of Israel.) Ahab's family were idolators, but Yehu himself maintained the golden calf idols, so G-d would do to Yehu as Yehu did to Ahab.
G-d told Hoshea to name his daughter Lo-Ruchama (no pity), since G-d will not be lenient with Israel forever. He will mete out strict judgment to the nation of the Ten Tribes, although He would have mercy on Judah and save them from Assyrian exile.
G-d instructed Hoshea to name his younger son Lo-Ami (not my nation), saying that they are no longer His people and He will no longer continue to be their G-d.
There is a disagreement among the commentators as to whether Hoshea actually married a prostitute and had children, if it was a prophetic vision, or just a metaphor. The Talmud (Pesachim 87a-b) and Rashi seem to take the literal approach, so we are treating it literally here.