In Leviticus 27:16, the value of the homer of barley seed signifies the full estimation of good and truth. (Arcana Coelestia 8468)

In Matthew 27:9, the thirty pieces of silver signify the small esteem in which the Lord's work of redemption and salvation was held. (Arcana Coelestia 2276[2, 3])

In Luke 12:7, a sparrow signifies what is of little account in comparison with human beings. (Apocalypse Explained 548[10])

2276. 'Perhaps thirty will be found [there]' means some existence of conflict. This is clear from the meaning of the number 'thirty'. The reason 'thirty' means some existence of conflict, thus a small amount of conflict, is that this number is the product of 'five', meaning that which is small, times 'six', meaning toil or conflict, as shown in Volume One, in 649, 720, 737, 900, 1709.

[2] Hence also that number, wherever one reads it in the Word, means something relatively small, as in Zechariah,

I said to them, If it is good in your eyes, give me my wages; and if not, withhold them. And they weighed out my wages, thirty pieces of silver. And Jehovah said to me, Throw it to the potter, the magnificent price I was valued at among them. And I took the thirty pieces of silver and threw it into the house of Jehovah, to the potter. Zechariah 11:12-13.

This stands for how small a value those people placed on the Lord's merit, and on redemption and salvation from Him. 'The poster' stands for reformation and regeneration.

[3] This explains the reference to the same thirty pieces of silver in Matthew,

They took the thirty pieces of silver, the price set on him whom they had bought from the children of Israel, and gave them for the potter's field, as the Lord commanded me. Matthew 27:9-10.

From these words it is quite clear that 'thirty' here stands for the small price set on him. A slave, who was not considered to be worth much, was valued at thirty shekels, as is clear in Moses,

If the ox gores a slave or a servant-girl, the owner shall give to his master thirty shekels of silver; and the ox shall be stoned. Exodus 21:32.

How little a slave was considered to be worth is clear from verses 20-21, of that same chapter. In the internal sense 'a slave' stands for toil.

[4] The reason Levites were called upon for ministerial duty - which is described as one 'coming to perform military service and to do the work in the tent [of meeting] - from thirty up to fifty years of age', Numbers 4:3, 23, 30, 35, 39, 43, was that 'thirty' means those who were beginners, thus those who as yet could perform little of what was meant in the spiritual sense by 'military service'.

[5] There are other places in the Word besides these where 'thirty' is mentioned, such as in the requirement that with a young bull a minchah of three tenths [of fine flour] was to be offered by them, Numbers 15:9. Such was required because the sacrifice of an ox represented natural good, as shown above in 2180, and natural good is small in comparison with spiritual good, which was represented by the sacrifice of a ram, and smaller still in comparison with celestial good, which was represented by the sacrifice of a lamb, with which sacrifices a different number of tenths to the minchah were required, as is clear in verses 4-6 of that chapter, and also in Numbers 28:12-13, 20-21, 28-29; 29:3-4, 9-10, 14-15. These differing numbers of tenths, or proportions, would never have been commanded if they had not embodied heavenly arcana within them.

[6] 'Thirty' again stands for that which is small in Mark,

The seed which fell into good ground yielded fruit, growing up and increasing. One bore thirty-fold, and another sixty, and another a hundred. Mark 4:8.

'Thirty' stands for a small yield and for that which has laboured to only a small extent. Those numbers would not have been specified unless they had embodied the things meant by them.