in the sense of: "break the barrel and keep its wine", you cannot eat cake and have it/ you cannot break the barrel and keep its wine.
By analogy: a thing and its opposite. A demand that contains an internal contradiction. Or: it is impossible to enjoy both situations at once. 'You cannot eat the cake and also leave it whole.'
("And the Lord said to Satan, 'Behold, he is in your hand; only spare his life.' So Satan went out from the presence of the Lord and struck Job... Rabbi Yitzchak said: The pain of Satan is harder than that of Job; it is like a servant whose master says to him: 'Break the barrel but keep its wine.' Resh Lakish said: He is Satan, he is the evil inclination, he is the angel of death." - Bava Batra 16a)
Translation
Expression (Hebrew)
בִּבְחִינַת: "שְׁבֹר חָבִית וּשְׁמֹר עַל יֵינָהּ"
Definition (Hebrew)
בְּהַשְׁאָלָה: דָּבָר וְהִפּוּכוֹ. דְּרִישָׁה בַּעֲלַת סְתִירָה פְּנִימִית. אוֹ: אִי אֶפְשָׁר לְהֵינוּת מִשְּׁנֵי הַמַּצָּבִים כְּאֶחָד. 'לֹא נִתָּן לֶאֱכֹל אֶת הָעוּגָה וגַּם לְהַשְׁאִיר אוֹתָהּ שְׁלֵמָה'.
("וַיֹּאמֶר ה' אֶל הַשָּׂטָן הִנּוֹ בְיָדֶךָ אַךְ אֶת נַפְשׁוֹ שְׁמֹר, וַיֵּצֵא הַשָּׂטָן מֵאֵת פְּנֵי ה' וַיַּךְ אֶת אִיּוֹב וְגוֹ'- אָמַר רַבִּי יִצְחָק: קָשֶׁה צַעֲרוֹ שֶׁל שָׂטָן יוֹתֵר מִשֶּׁל אִיּוֹב, מָשָׁל לְעֶבֶד שֶׁאָמַר לוֹ רַבּוֹ: שְׁבֹר חָבִית וּשְׁמֹר אֶת יֵינָהּ. אָמַר ר"ל: הוּא שָׂטָן הוּא יֵצֶר הָרָע הוּא מַלְאַךְ הַמָּוֶת "-בָּבָא בָּתְרָא טז ע"א)