καὶ ὄψεται πᾶσα σὰρξ τὸ σωτήριον τοῦ Θεοῦ.
Luke concluded his quote of Isaiah with the saying that all flesh will see (καὶ ὄψεται πᾶσα σὰρξ) the salvation of God (τὸ σωτήριον τοῦ Θεοῦ). However, that is not from Isaiah who said that the glory of Yahweh would be revealed. All the people would see it together. I suppose that the intent is pretty much the same. Deutero-Isaiah was talking about Yahweh saving his people from Babylon. Thus, this might be considered a unique saying of Luke.