To sufficiently comprehend the evolution of the enslavement of B’nai Yisrael in Mitzrayim, it would seem that one needs to comprehend the closed nature of the two preceding Parshiyot; the concluding posuk of Vayigash (Sefer Breish’t, Perek 47, posuk 27);
And Yisrael dwelt in the land of Mitzriyim in the land of Goshen, and they acquired property in it and… multiplied greatly
And the first posuk of Vayechi ((Sefer Breish’t, Perek 47, posuk 28);
And Yaakov lived in the land of Mitzrayim for seventeen years…