The choral ode in Antigone, which Heidegger discusses in detail in this course talks about human beings and what they seek in life, about death, about what they achieve and fail to achieve. In the first lines of the ode, human being is places within the manifold manifestations of the uncanny, and called the most uncanny of all. Then the chorus sings of human pursuits to conquer the sea and the earth, the animals, but also language, governance and the everyday life. It concludes: “Everywhere venturing forth underway, experienceless without any way out/ he comes to nothing.”(HIE82) A similar tension of continuous effort which in the end does not satisfy the seeking, is also described in the realm of a πόλις, a particular historic site, into which human being is placed, and within which it lives, dealing with entities. The ode concludes with not allowing those who carry out such things anywhere near the hearth.
Heidegger says, that the decisive word of the beginning of the choral ode, as well as of Greek tragedy in general, is τὸ δεινόν, which Heidegger translates as das Unheimliche, the uncanny. According to Sophocles, the uncanny is manifold, yet human being is the most uncanny of all. (HID74, HIE61) The notion of uncanniness is familiar to us from Being and Time, where Unheimlichkeit is a mood that accompanies angst as the basic “state-of-mind”. It is an uncomfortable feeling of “not being at home”, and human beings flee from uncanniness by turning away from it and towards the entities within the world, which provide the familiarity, security and possibility to lose oneself in one’s daily concerns and involvements. (SZ188-190) The opposite to the uncanniness in Being and Time is “being-at-home”, “Zuhause-sein”, which is the “tranquillized self-assurance” of the “they”. This “being-at-home” is only seen in a sense of Dasein’s inauthentic turning away from its own being and finding comfort in the involvement with other entities. However, this “at home” (“zuhause”) of Being and Time is not always the same as “at home” (“daheim”) and “homely” (“heimisch”) of the Ister lecture course.
In the Ister lecture course, Heidegger chooses to translate Sophocles’ τὸ δεινόν as das Unheimliche, the uncanny, because the word “uncanny” (“unheimlich”) is related to the word “unhomely” (“unheimisch”), and both these words have within them the root “-home-”(“-heim-“). It is this original meaning of the word “unheimlich”, which is related to home, that Heidegger is interested in.
“We mean the uncanny in the sense of that which is not at home – not homely in that which is homely. It is only for this reason that the un-homely [das Un-heimiche] can, as a consequence, also be “uncanny” [“unheimlich”] in the sense of something that has an alienating or “frightening” effect that gives rise to anxiety.”  (HIE 71)
Heidegger continues, by making another step beyond explaining the connection between the uncanny and the unhomely, by suggesting an interpretation of Sophocles, that talks of a human being, as someone whose care or concern is to become homely:
“In that case, Sophocles’ word, which speaks of the human being as the most uncanny being, says that human beings are, in a singular sense, not homely, and that their care is to become homely.”  (HIE 71)