Tenderness, according to Heidegger, is used by Hölderlin to indicate the native essence of the Greek: their art of showing, letting appear what shows itself purely and thereby presences. For the Greeks, what brings the splendour of the presencing to appearance is the athletic warlike struggle of heroes (also consider Heraclìtus and Pìndar) and the power of reflection (die Reflexionskraft) (HEH 166). These two (athletic struggle and power of reflection) belong together in what Hölderlin names tenderness. They name the highest showing, as where. poetically dwelling (and for the Greeks all art is grounded in poetic song), man brings all appearing - earth, and heavens, and the holy - to a stand (HEH 162, 164). Clearly, as the bringing to disclosure, tenderness does not, as we might non-originarily suppose, mean anything sentimental for Hölderlin (HEH 160). Tenderness is essentially both joyful-reaching (erfreuend-reichendes) and simple-receiving (einfach-empfangendes). It too opens the earth to heaven. When the opening of heaven and earth reaches things and world thus comes forth, there is joy. The joy, received when it reaches out, comes as simplicity, in the simple. That is why the poet sings of joy in the simple and strives to stay simple in his reception of the joy which comes in the singing language-full coming of the disclosure of thing and world.
P. 414HEH: Hölderlin's Erde und Himmel.