Own
In many cases, the spiritual meaning of "own," both as a verb and as an adjective, is relatively literal. When people are described as the "Lord's own," however, it specifically means those people who know Him and have His Word. This has taken various forms since the dawn of humanity; in the prehistoric church known as the "Most Ancient Church" the Lord's truth -- the direct expression of His love -- flowed into people directly. In the Ancient Church the Lord's Word was recognized in nature and in the form of deeply representative stories, some of which were passed on to us in the early chapters of Genesis. Among the Children of Israel the Lord's Word was expressed through the Ten Commandments, the laws of Moses, the very history of the nation of Israel and the various psalms and prophecies. The early Christians had those stories along with the teaching and inspiration of Jesus himself. We now have the whole Bible, including the teachings of Jesus, and can understand the Bible's true meaning. Each of these churches, then, was at some point the Lord's own.
Arcana Coelestia #773
773. 'They' means in general the member of the Church or everything that belonged to that Church. This is clear from the fact that 'they' refers to the characters who have just been mentioned by name, Noah, Shem, Ham, and Japheth. Although there are four of them, they nevertheless together constitute a single whole. For Noah, who is used in general to mean the Ancient Church, includes, as the parent or seed, the Churches that sprang from it. Hence 'they' means the Ancient Church. All of the Churches which are called Shem, Ham, and Japheth, together constitute the Church called the Ancient Church.