The phrase 'put words in someone's mouth' has a biblical origin that is more literal than metaphorical: Joab actually scripts a speech and instructs a woman to deliver it word for word in 2 Samuel 14. The episode is a masterclass in court intrigue, and the phrase it generated has become one of the most widely used expressions in English for any form of false attribution or imputed statement.
The context in 2 Samuel 14 is the aftermath of Absalom's killing of his half-brother Amnon. David has banished Absalom for the killing, and Joab - David's chief general and political operator - wants to engineer Absalom's return. He arranges for a wise woman from Tekoa to come to David with a fabricated family dispute. Joab had 'put all these words in her mouth' (2 Samuel 14:3); later in the narrative the woman herself acknowledges this when David presses her (14:19): 'Did not Joab bid thee all this? And the woman answered... none can turn to the right hand or to the left from ought that my lord the king hath said: for thy servant Joab, he bade me, and he put all these words in the mouth of thine handmaid.'
The phrase thus captures a specific form of manipulation: scripting another person's speech so that they appear to be speaking from their own experience and authority while actually delivering your argument. The woman's story is compelling because it seems to come from her own suffering; its true origin in Joab's political calculation is what makes it manipulative. The success of such manipulation depends on the audience not knowing the speech was scripted.
In modern English 'putting words in someone's mouth' has expanded beyond scripted speech to cover all forms of false attribution. The most common use is the accusation: 'Don't put words in my mouth' - meaning, you are attributing to me positions, beliefs, or statements that I did not make. This use is near-universal in debate, journalism, politics, and personal argument. When someone characterizes another's position inaccurately - whether deliberately or through misunderstanding - the accused party reaches for this phrase.
In legal contexts the phrase has specific weight in the context of leading questions and coached testimony. A witness who has been coached to say certain things has had words put in their mouth; a lawyer who frames a question in a way that suggests the answer is engaging in a form of verbal mouth-filling. Legal procedural rules against leading questions in direct examination are designed precisely to prevent this.
In journalism the phrase surfaces in complaints about out-of-context quotation, inaccurate paraphrase, and the characterization of sources' views. Journalists who attribute statements to sources that those sources deny having made are accused of putting words in mouths. The phrase thus functions as a standard tool of accountability in public discourse.
The biblical episode is more psychologically complex than the simple accusation structure of modern usage. Joab's manipulation is effective - David is moved by the woman's story - but it also backfires: Absalom's return, secured through Joab's clever manipulation, eventually leads to the rebellion that nearly costs David his throne. The words Joab put in the woman's mouth produced the outcome he wanted in the short term and contributed to catastrophe in the long term - a pattern that the phrase, in its modern accusatory use, does not capture but that the original narrative does.