Bereshit 50:3

וימלאו לו [AND FORTY DAYS] WERE FULFILLED — They (the physicians) completed the days of embalming until forty days were completed for him. ויבכו אתו מצרים שבעים יום AND THE EGYPTIANS WEPT FOR HIM THREESCORE AND TEN DAYS — viz., forty days during the period of embalming and thirty more days for mourning. They wept for him during so long a period because a blessing had come to them on his arrival in Egypt for the famine then ceased and the waters of the Nile again increased (Midrash Tanchuma, Nasso 26).

וַיִּמְלְאוּ־לוֹ֙ אַרְבָּעִ֣ים י֔וֹם כִּ֛י כֵּ֥ן יִמְלְא֖וּ יְמֵ֣י הַחֲנֻטִ֑ים וַיִּבְכּ֥וּ אֹת֛וֹ מִצְרַ֖יִם שִׁבְעִ֥ים יֽוֹם׃

And forty days were fulfilled for him: for so are fulfilled the days of those who are embalmed: and Miżrayim wept for him seventy days.