The author presents a new interpretation of «rus/Rus» and «Russian land» concepts origin and traces their genesis back to the specific mentality of ancient Russian scribes of the 11th-15th century. The author offers a new perusal of the phrase: «отъ варяг бо прозвашася русью» (…«took their name «rus» from varangians»). The conventional interpretation of this phrase from the «Povest' vremennykh let» («Chronograph») original manuscript corpus is that the very name «rus» was derived from a name of some varangian tribe which bequeathed its name to another ethnic group. The author insists that the phrase should be read as follows: «varangians called them „rus“». According to mentality and world view of ancient Russian scribes the name «rus» was derived under influence of Byzantine chronicles from name of the elected Biblical tribe Pώz. Upon acceptance of Christianity in Rus a new concept «Russian land» appeared. That concept described a territory where the Orthodox faith dominated. As Constantinople fell in 1453 and Moscow Rus emancipated itself from the Mongol-Tatar yoke in 1480 notions «Russian» and «believer in Orthodox faith» became synonymic while Moscow Rus as the only independent Orthodox state was perceived as the guardian of the Orthodox faith until the doomsday which was expected to come in year 7000 (1492).