פּירוש אויף דברים 17:4

נכון [AND, BEHOLD, IT BE TRUE, AND THE THING BE] CERTAIN — i.e. the evidence of the witnesses is in agreement (מְכֻוָּן‎)

investigate well here means intensely (as in “I am greatly angry” [Jonah 4: 9]). The word well is closely related to the Hebrew word for “good”.

והוגד לך ושמעת, “and you have been informed, and you will hear, etc.” The apparent repetition of the same thought means that whenever and wherever this accusation is brought to your attention you must immediately commence an investigation. As soon as you establish that the rumours you have heard are factual, you have to lead the guilty party to his or her place of execution where you will stone the guilty party to death.