Bede

And her neighbors and relatives heard that the Lord had shown great mercy toward her, and they rejoiced with her. The birth of the saints brings joy to many because it is a common good. For justice is a communal virtue. Therefore, at the birth of a just person, a sign of future life is foretold, and the grace of the forthcoming virtue is prefigured with the joyful exultation of neighbors.

On the Gospel of Luke ↗

Bonaventure

Joyful also was it in the neighborhood by reason of the celebrated and common report; on account of which it says: And her neighbors and kinsfolk heard that the Lord had magnified his mercy with her, and they congratulated her. And thus was fulfilled what the Angel had foretold: "And many shall rejoice at his birth," namely the neighbors and kinsfolk, because it belongs especially to such people to rejoice together; below in the fifteenth chapter: "The woman who found the lost drachma calls together her friends and neighbors, saying: …

Commentary on Luke, Chapter 1 ↗