Genesis 39:2

And the Word of the Lord was Joseph's Helper, and he became a prosperous man in the house of his Mizraite master.

ויהי ה' את יוסף, to save him from anyone who would take advantage of him.

ויהי איש מצליח, he achieved every venture that he set out to accomplish.

ויהי בבית אדוניו המצרי, he would perform tasks in his master’s private room. The meaning of the word היה here is the same as the meaning of the word עמד elsewhere, i.e. stationed, remaining in a fixed position. Examples of the word היה occurring in this sense are found in Deuteronomy 31,26 והיה שם, “it would remain there.” Compare also Deuteronomy 10,5 ויהיו שם כאשר צוני ה', “they remained there as the Lord had commanded me.”

ויהי ה' את יוסף ויהי איש מצליח, he was successful in all things he undertook on his own behalf and also was successful in the house of his Egyptian master. Every task that was assigned to him he managed to carry out successfully.

ויהי ה' את יוסף , “and the Lord was with Joseph;” the Midrash sees in this line a lesson for us to compare G–d’s method of befriending us to how human beings befriend their masters or superiors. As long as their superiors are successful and amass glory the underlings surround the king and flatter him nonstop. As soon however, as the king or master falls on hard times, his former “friends,” and flatterers abandon him as they would a ship about to sink. The reverse is true of Hashem. As soon as Joseph fell on hard times, G–d went out of His way to show him that far from having abandoned him, on the contrary, He now went out of His way to make life easier for him. He supported him when he became viceroy of Egypt for 80 years, as well as when he was still a slave in the house of Potiphar, and even when jailed for supposedly having tried to rape his wife. It is remarkable that also Joseph’s way of responding to the way the brothers had treated him were quite different from the way ordinary people would have reacted to this given the chance. Normally, poor people display some fear of G–d, as He is the only one from whom they can expect help. Joseph, even when in a position of power, repeatedly refused to do something that G–d would not approve of (Compare Genesis 42,18 as well as 39,9) An alternate interpretation of the line: ויהי ה' את יוסף. Imagine someone blessed with ten children, each one of whom lives in a different country. Instead of visiting them all in rotation, he concentrated on spending time with the youngest, as he was less well endowed than his brothers, and depended more on advice and assistance from his father. Take another parable illustrating our subject. A wine merchant had loaded ten donkeys with barrels of wine and began to lead them on the public highway. Suddenly one donkey veered and entered the house of a pagan. Right away the owner abandoned all the other nine donkeys out of concern that a pagan might touch the wine on the back of the last mentioned animal and make it unfit for Jews to drink from. Similarly, as soon as G–d saw that Joseph had been brought to the house of an Egyptian who was now his master, He hurried to supervise his fate to protect him from harm. He was afraid that unless He did so, Joseph might learn to copy the lifestyle of his master.