Q. What was the estate of Christ’s humiliation?
A. The estate of Christ’s humiliation was that low condition, wherein he for our sakes, emptying himself of his glory, took upon him the form of a servant, in his conception and birth, life, death, and after his death, until his resurrection.

Q. How did Christ humble himself in his conception and birth?
A. Christ humbled himself in his conception and birth, in that, being from all eternity the Son of God, in the bosom of the Father, he was pleased in the fulness of time to become the son of man, made of a woman of low estate, and to be born of her; with divers circumstances of more than ordinary abasement.

Q. How did Christ humble himself in his life?
A. Christ humbled himself in his life, by subjecting himself to the law, which he perfectly fulfilled; and by conflicting with the indignities of the world, temptations of Satan, and infirmities in his flesh, whether common to the nature of man, or particularly accompanying that his low condition.

(Questions XLVI, XLVII and XLVIII of the Westminster Larger Catechism.)