Acts 7:6

And God had spoken about this [beforehand] by saying that Abraham's descendants would live in a foreign country and that they would [eventually] be ill-treated as slaves for four hundred years.

Acts 13:17

The God of Israel chose our forefathers [to be His people] and made them a great people when they lived in Egypt, and with His mighty power He led them out of it.

Galatians 3:16-17

Now [specific] promises were made to Abraham and to his seed [i.e., descendants]. [God] did not say "seeds" [plural] as though He were referring to many persons but "seed" [singular] showing that He meant one [descendant]; [Gen. 13:15 says] "And to your seed," referring to Christ.

Hebrews 11:9

By [having] faith, he became an alien in the foreign country that had been promised to him. He lived in tents, along with Isaac [his son] and Jacob [his grandson], who [also] were to receive the same inheritance he had been promised.

Treasury of Scripture Knowledge

Summary

Now the sojourning of the children of Israel, who dwelt in Egypt, was four hundred and thirty years.

Four hundred

Bible References

Sojourning

Acts 13:17
The God of Israel chose our forefathers [to be His people] and made them a great people when they lived in Egypt, and with His mighty power He led them out of it.
Hebrews 11:9
By [having] faith, he became an alien in the foreign country that had been promised to him. He lived in tents, along with Isaac [his son] and Jacob [his grandson], who [also] were to receive the same inheritance he had been promised.

Four hundred

Acts 7:6
And God had spoken about this [beforehand] by saying that Abraham's descendants would live in a foreign country and that they would [eventually] be ill-treated as slaves for four hundred years.
Galatians 3:16
Now [specific] promises were made to Abraham and to his seed [i.e., descendants]. [God] did not say "seeds" [plural] as though He were referring to many persons but "seed" [singular] showing that He meant one [descendant]; [Gen. 13:15 says] "And to your seed," referring to Christ.