Blink of an eye

This phrase comes from Rashi on the Possuk in (Shmos 12:41) that says: וַיְׁהִׁי מִׁקֵץ שְׁלשִׁים שָנָה וְׁאַרְׁ בַע מֵאוֹת שָנָה וַיְׁהִׁי בְׁעֶצֶם הַיוֹם הַזֶה יִָֽצְׁאוּ כָל־צִׁבְׁאוֹת ה׳ מֵאֶרֶץ מִׁצְׁרָיִׁם “It was at the end of 430 years, and it came to pass in that very day, that all the legions of HaShem went out of the land of Mitzrayim.” And Rashi states: This tells us that as soon as the end of this period arrived, the Omnipresent did not keep them even as long as the ‘blink of an eye’. On the fifteenth of Nissan, the angels came to Abraham to bring him tidings. On the fifteenth of Nissan Isaac was born; on the fifteenth of Nissan the decree of “between the parts” was decreed. [from Mechilta]