Quick note, the condescension of God referred to in 1 Nephi 11:26 refers to Christ’s condescension in coming to a body of flesh and being slain for the sins of the world.
But the condescension of God referred to in 1 Nephi 11:16 refers to the Father’s condescension in marrying and having a child through Mary.
1 Nephi 11:16 And he said unto me: Knowest thou the condescension of God?
17 And I said unto him: I know that he loveth his children; nevertheless, I do not know the meaning of all things.
18 And he said unto me: Behold, the virgin whom thou seest is the mother of the Son of God, after the manner of the flesh.