Matthew Poole and continuators on Genesis 39:4

4 And Joseph found grace in his sight, and he served him , and he made him overseer over his house, and all that he had he put into his hand .

Not now as a slave, but in an higher degree.

(i. e.) Committed to his care and management, as Gen. 16. 6. Object. How could this be, when Ioseph understood not the Egyptian Tongue? Answ. Ioseph doubtless when he came thither did, as much as possibly he could, endeavour to get the knowledge of that Language, and being a person of excellent parts would soon obtain it, especially because of the great affinity between that Language and his own. Nor must we think that Ioseph was thus highly advanced in an instant but by degrees, step by step, and after some considerable time.