Richard Challoner

His left hand: Words of the church to Christ. His left hand, signifying the Old Testament, and his right hand, the New.

Who is this: The angels with admiration behold the Gentiles converted to the faith: coming up from the desert, that is, coming from heathenism and false worship: flowing with delights, that is, abounding with good works which are pleasing to God: leaning on her beloved, on the promise of Christ to his Church, that the gates of hell should not prevail against it; and supported by his grace conferred by the sacraments. Under the apple tree I raised thee up; that is, that Christ redeemed the Gentiles at the foot of the cross, where the synagogue of the Jews (the mother church) was corrupted by their denying him, and crucifying him.

Our sister is little: Mystically signifies the Jews, who are to be spoken to: that is, converted towards the end of the world: and then shall become a wall, that is, a part of the building, the church of Christ.