Deut 9:18

וָֽאֶתְנַפַּל֩ לִפְנֵ֨י יְהוָ֜ה כָּרִאשֹׁנָ֗ה אַרְבָּעִ֥ים יוֹם֙ וְאַרְבָּעִ֣ים לַ֔יְלָה לֶ֚חֶם לֹ֣א אָכַ֔לְתִּי וּמַ֖יִם לֹ֣א שָׁתִ֑יתִי עַ֤ל כָּל־חַטַּאתְכֶם֙ אֲשֶׁ֣ר חֲטָאתֶ֔ם לַעֲשׂ֥וֹת הָרַ֛ע בְּעֵינֵ֥י יְהוָ֖ה לְהַכְעִיסֽוֹ׃

Then I fell down before the LORD for forty days and forty nights, as I had done the first time. I did not eat bread or drink water because of all the sin you had committed in doing what was evil in the sight of the LORD and provoking Him to anger.