A "field" in the Bible usually represents the Lord's church, and more specifically the desire for good within the church. It's where good things start, take root, and grow. When you have a desire to be a good person and to do good things, the natural first questions are "What does that mean?", "What should I do?", "What can I do?". You look for ideas, concepts, direction. Once you figure out something you want to do or a change you want to make in yourself, you seek specific knowledge. If you want to volunteer at a food pantry, say, you'd need to know whom to call, when they need help, where to go, what to bring. Armed with that knowhow, you're ready to get to work. That process could be compared to food production. You start with a field -- which is that desire to be good. Then you plant seeds -- those ideas and concepts. Those seeds sprout into plants -- the specific facts and knowledge needed for the task (easily seen in the food pantry example, but also true with deeper tasks like "being more tolerant of my co-workers" or "taking more time for prayer," or "consciously being a more loving spouse"). Finally, those plants produce food -- the actual good thing that you go and do. The Writings also say that in a number of cases a "field" represents the doctrine, or teachings, of the church. This sounds markedly different. The desire for good is emotional, a drive, a wanting; doctrine is a set of ideas. But for a church to be true, its doctrine must be centered on a desire for good, and must lead people toward doing what is good. So sound doctrine is actually closely bound up with the desire for good.

3963. 'Afterwards she bore a daughter' means the affection for all these, and also means the Church of faith in which good is present. This is clear from the meaning of 'a daughter' as an affection, and also as a Church, dealt with in 2363. But as to what the object of the affection is, or what kind of Church is meant, this is evident from whatever is added on to the word 'daughter'. For example, it is evident from the addition of 'Zion' after 'daughter' that the celestial Church, which is called 'the daughter of Zion', is meant; from the addition of 'Jerusalem' that the spiritual Church, which is referred to as 'the daughter of Jerusalem', is meant, and so on. In the present verse, in which nothing is added on to it, 'daughter' means the Church of faith in which good is present. For up to this point the subject has been the general truths which constitute faith in which good is present, and the reception and acknowledgement of those truths, that is to say, the truths that were meant, as has been shown, by the ten sons of Jacob dealt with above. And since immediately after these sons reference is made to the birth of a daughter it is evident from the train of thought that a Church is meant in which all these truths are present.

[2] Whether you call it the Church of faith in which good is present, or you call it the spiritual Church, it amounts to the same; or again if you call it the affection for all these, that is, all these general truths. For it is from the affection for truth in which good is present, and the affection for good from which truth springs, that the Church has its being, not from the affection for truth in which good is not present or the affection for good from which truth does not spring. People who are governed by an affection for truth but not by the good from which truth springs, that is, who do not live according to truths, are much mistaken when they say that they belong to the Church. Though within a congregation, they are outside the Church, for they are governed by the affection for evil to which truth cannot be joined. Their affection for truth does not originate in the Lord but in themselves, for they have themselves in view, their intention being by means of the truth they know to earn repute, and thereby important positions and wealth. But they do not have the Church in view, or the Lord's kingdom, let alone the Lord. But people governed by the affection for good from which truth does not spring do not belong to the Church even though they are within a congregation, for they are governed by natural good, not by spiritual, and allow themselves to be led into every kind of evil and also of falsity, provided that evil is made to look like good and falsity to look like truth, see 3470, 3471, 3518.