The Meaning of Numbers: The Number 400
The number 400, which is arrived at by multiplying 8 by 50, symbolizes in the Bible a divine perfect time period.
A 400 year period exists from God's fulfilling of his pledge to Abraham in Isaac's birth to the children of Israel leaving Egyptian bondage. Stephen, in his testimony before religious leaders just before his martyrdom, mentions the starting point of this count (Acts 7:6), which agrees to what the Eternal stated in Genesis 15:12 - 13.
This is what God said to him (Abraham, the father of the faithful): 'Your descendants will live in a foreign country, where they will be slaves and will be badly treated for four hundred years (Acts 7:6).
Appearances of the number four hundred
Abraham's wife Sarah is the ONLY woman in the entirety of Scripture where her age at death is stated (Genesis 23:1). When she died at 127 Abraham bought the cave of Machpelah, located in Mamre (Hebron), for 400 shekels of silver (verses 3 - 20). He used the cave as a burial location for his beloved wife.
When Abraham himself died at the age of 175, his sons Isaac and Ishmael buried him in the same cave (25:8 - 10). When Isaac's wife Rebekah passed on she too was placed in the cave, as well as Isaac himself (who was buried by sons Esau and Jacob - Genesis 35:29).
Meaning of the number 430
God delivered Israel's firstborn from death on Nisan 14. Then, at the beginning of Nisan 15 at sunset, the children of Israel began to leave Egypt by night. This night is called 'the night to be much observed unto the Lord' (Exodus 12:40 - 42, Numbers 33:3, Deuteronomy 16:1).
On this same day as the 'night to be much observed,' 430 years earlier, God told Abraham in a vision that his descendants through Isaac would end up as slaves in a foreign country. God would, however, release them from this bondage after 400 years (Genesis 15:12 - 16).
Exactly 430 years later, on the same night, this prophecy was fulfilled as the children of Israel left Egypt on the 15th day of the first month (Exodus 12:40 - 41). On the same night - in order to guarantee His covenant promises to Abraham - the Lord passed between the parts of sacrificial animals, as evidenced by a burning lamp and a smoking furnace, which wholly consumed the sacrifices (Genesis 15:17 - 20).
In performing this ceremony, God was pledging His future death as the perfect sacrifice for the sins of the world - guaranteeing the future 'rest' from sin for all who inherit eternal life.
On the same day as Abraham's vision and the children of Israel leaving Egypt, the 15th day of the first month in 30 A.D., as the sun was setting to end the 14th - Jesus' body was placed in the tomb. Thus, Jesus began His three days and three nights in the heart of the earth.
The significance of the number four hundred and thirty comes from it being the total years from the CALL of Abraham (Genesis 12) and the promises given to him to the exodus of the children of Israel out of Egyptian bondage (Exodus 12).
Additional info on the Biblical Meaning of 430
The prophet Ezekiel was commanded by God to first lay on left side for 390 days then on his right side for 40 days (Ezekiel 4:1 - 6) for a total of 430.