Yehosef

 אמרו לו א"כ יהא יודע בשבעים לשון בא גבריאל ולימדו שבעים לשון לא הוה קגמר הוסיף לו אות אחת משמו של הקב"ה ולמד שנאמר (תהלים פא, ו) עדות ביהוסף שמו בצאתו על ארץ מצרים (שפת לא ידעתי אשמע) ולמחר כל לישנא דאישתעי פרעה בהדיה אהדר ליה 

They said to him: If that is so and he is a child of royalty, he should know the seventy languages that all kings’ children learn. The angel Gabriel then came and taught him the seventy languages, but he could not learn all of them. Gabriel then added one letter, the letter heh, to Joseph’s name from the name of the Holy One, Blessed be He, and then he was able to learn the languages, as it is stated: “He appointed it in Joseph [Yehosef] for a testimony, when he went forth against the land of Egypt, the speech of one that I did not know I heard” (Psalms 81:6). And the next day, when he appeared before Pharaoh, in every language that Pharaoh spoke with him, he answered him.

Why specifically the extra Heh? Because the Heh consists of a yud and a daled =14. The Heh itself =5.

14x5=70