Oil -- typically olive oil -- symbolizes the good that comes from celestial love. Celestial love is love of the Lord, the highest and purest love we can have. The good of celestial love is the desire to be good springing from celestial love: Wanting to do the Lord's will because you love Him. That's not a state many reach, even in heaven, but it's a beautiful goal. This representation makes sense based on the idea that the sun -- the source of all natural light and heat, and thus all natural life -- represents the Lord, the source of all spiritual light, heat and life. Burning oil was the most pure fire available in Biblical times, thus the closest representation of the sun people could create.

3577. 'Like the odour of the field' means as the good ground from which truth is acquired. This is clear from the meaning of 'the odour of the field' as the perception of truth acquired from good, like the scent from the harvest in the field - 'the field' meaning good ground, see 3500. The reason 'odour' means perception is that all the delight that good yields and all the pleasantness that truth gives, which people perceive in the next life, also manifest themselves there as corresponding odours, see 1514, 1517-1519. From this and from correspondences it is evident that 'odour' is nothing else than the power of perception, though a natural power of perception corresponding to a spiritual power of it.