1 Kings 16:11
And it came to pass, when he began to reign, as soon as he sat on his throne, that he slew all the house of Baasha: he left him not one that pisseth against a wall, neither of his kinsfolks, nor of his friends. And it came to pass, when he began to reign, as soon as he sat on his throne, that he slew all the house of Baasha: he left him not one that pisseth against a wall, neither of his kinsfolks, nor of his friends.
1 Kings 3-21 is a wholly historical record covering the time after David. The verse belongs to the history of the divided kingdom, in the succession of the kings of Israel as Nadab, and Baasha, and Elah, and Zimri, and Omri, and the wicked Ahab, contemporary with the reigns of Abijah and Asa in Judah. It falls in the account of Israel's great apostasy in the days of Elijah, when God called the people back through His prophet and found a faithful remnant.
Baasha had slain Nadab and ended the house of Jeroboam, then reigned twenty-four years and was followed by his son Elah, whose drunken reign lasted two years. Elah son of Baasha thus repeated the history of Nadab son of Jeroboam by reigning only two years and meeting death by violent hands. Zimri the captain slew Elah, and as soon as he sat on his throne he slew all the house of Baasha, killing every male member and leaving no male relative or friend and no close associates alive, so the house died with Elah.
In doing this Zimri was seeking to eliminate rivals when he took the throne. The killing fulfilled the word of the prophet Jehu that Baasha and his house would come to the same end that befell the house of Jeroboam. Zimri himself reigned only seven days before he was slain by Omri, from whom sprang the wicked Ahab. The record is a sad one full of important lessons from a time when the general moral tendency in Judah and Israel was downward though with times of reviving, showing that whenever the people sought God He wrought for them and through them abundantly, and showing the responsibility resting upon leaders, since faithful kings and priests molded the people immensely while leaders who failed to lead in right ways caused the people to fail with them.