This change of name that was brought about by the prefixing of the letter Yod at last silenced the lamentations of this letter. For ever since God had changed Sarai's name to Sarah, the letter Yod used to fit about the celestial Throne and lament: "Is it perchance because I am the smallest among the letters that Thou has taken me away from the name of the pious Sarah?" God quieted this letter, saying: "Formerly thou wert in a woman's name, and, moreover, at the end. I will not affix thee to a man's name, and, moreover, at the beginning." This promise was redeemed when Hoshea's name was changed to Joshua.
The Tiny Letter Yod That Complained When God Changed Sarai's Name
Legends of the Jews 4:92