the innermost room of a house: the secluded back chamber, used both to store what is valuable and to be alone and unseen
The word names one feature of an ancient house: its deepest interior room. In everyday speech it usually meant the storeroom or pantry, the place where grain, money, and valuables were kept. Because that room was the most interior one and often the only room that could be locked, it was also the most private space in the house.
That double duty is why the same word can mean "storeroom" in one verse and "private room" a few lines later. Luke 12 shows both within a single chapter: birds have no storeroom in which to hoard (12:24), yet whatever is whispered in the inner rooms will one day be shouted from the rooftops (12:3).
When Jesus tells people to go into their inner room and shut the door to pray (Matthew 6:6), he is naming the humblest, most ordinary private space, even the back pantry of a one-room house, as the place to meet God unseen. The force of the image is a turn away from showy public prayer, not a rule about which room to use.
Nuances
Whether the inner room of Matthew 6:6 is specifically the storeroom of a modest Galilean house or more broadly any private inner chamber, such as a bedroom.
- majorityThe storeroom: in a one- or two-room peasant house the small interior pantry was the only room with a door that could be locked, so Jesus names it as a private space available even to the poor.; J. Jeremias, Jerusalem in the Time of Jesus; R. T. France, The Gospel of Matthew (NICNT), pp. 239, 244; U. Luz, Matthew 1-7 (Hermeneia), pp. 300-301
- minorityAny private inner chamber, including a bedroom, following the Greek Old Testament's use of the word for the Hebrew inner room.; J. A. Broadus, Commentary on the Gospel of Matthew; A. Plummer, An Exegetical Commentary on the Gospel according to St. Matthew