God cut the time short in righteousness because the number of years they were afflicted were not up to 400 years. Read it in KJV also.
The word used in this version in conjunction with 400 years was mistreated which KJV translated as afflicted.
- How old was Joseph when he died? (110 years; Gen 50:26).
Minus his age before he was sold to slavery (17; Gen 37:2) from 30 years when he became prime minister of Egypt (30-17=13). This means Joseph suffered as a descendant of Abraham in Egypt for 13 years.
Let's keep this figure (13 years) till the end when we shall make use of it as part of the number of years for which the descendants of Abraham were afflicted in Egypt.
So minus 30 years from 110 years = 80 years.
Then Minus 2 years of famine which had happened at which point Joseph ordered his father and all his household to come over to Egypt (Gen. 45:2) from 80 years, that gives 78 years.
Therefore, for 78 years of Joseph's lifetime, Israelites enjoyed in Egypt.
Beginning of years of affliction of all Abraham's descendants in Egypt
It was after Joseph had died that Israelites' affliction by the king who did not know Joseph began.
Note also that it was not immediately after Joseph died that the affliction of Israelites began. But the Bible is silent on at what exact time after Joseph's death that king who afflicted them began to reign; and at what point of his reign he started to afflict them.
So Israelites' stay of 430 years is mentioned in Exo. 12:40 included the years of enjoyment plus the years they were afflicted.
Number of Years of their affliction
To know the number of years they were afflicted, we have to minus 78 from 430 (430-78) = 352 years.
If you want to add 13 years of Joseph's suffering as a slave (13 years) to this 352 years;
352 + 13 = 365 years of suffering for Israelites in Egypt.
But again, note that it was not on the dot that Joseph died that their suffering began!
God is perfect.
He cut their suffering years short in righteousness by responding to their cry and signings quickly.
In the same way, he will cut short the number of years of the present-day Israelites will suffer before salvation will appear to them because they will cry unto God. And they have started crying now at the wailing wall.