This verb means to inquire carefully or determine something with precision. Both occurrences appear in Matthew's infancy narrative concerning Herod and the magi. In 2:7, Herod secretly calls the wise men and ἠκρίβωσεν—ascertained exactly—the time the star appeared. In 2:16, when the magi don't return, Herod kills all boys in Bethlehem according to the time ὃν ἠκρίβωσεν—which he had carefully determined. The verb emphasizes Herod's methodical precision in gathering intelligence for his murderous plot, tragically demonstrating how careful investigation can serve evil purposes.