You labored and opened; labor and close it
As you took the trouble to make the opening, so you must now take the trouble to close it. Figuratively: if you labored to do something for your own benefit that causes harm to others, you must restore things to their previous state so that no damage is caused.
("A case of a man who opened his windows onto the courtyard of the partners, and he came before Rabbi Yishmael bar Rabbi Yosei. He said to him: You have exerted yourself, my son; you have exerted yourself. And he came before Rabbi Ḥiyya, who said: You labored and opened; labor and close it" - Bava Batra 59b)
Translation
Expression (Hebrew)
יָגַעְתָּ וּפָתַחְתָּ- יְגַע וּסְתֹם
Definition (Hebrew)
כְּמוֹ שֶׁטָּרַחְתָּ לַעֲשׂוֹת אֶת הַפֶּתַח, כָּךְ אַתָּה צָרִיךְ לִטְרֹחַ עַכְשָׁו לְסָגְרוֹ. בְּהַשְׁאָלָה: כְּמוֹ שֶׁטָּרַחְתָּ לַעֲשׂוֹת מַשֶּׁהוּ לְטוֹבָתְךָ וְיֵשׁ בּוֹ נֶזֶק לְזוּלַת, כָּךְ אַתָּה צָרִיךְ לְהָשִׁיב אֶת הַדְּבָרִים לְקַדְמוּתָם כְּדֵי שֶׁלֹּא לִגְרֹם נֶזֶק.
("מַעֲשֶׂה בְּאָדָם אֶחָד שֶׁפָּתַח חַלּוֹנָיו לַחֲצַר הַשֻּׁתָּפִין, וּבָא לִפְנֵי ר' יִשְׁמָעֵאל בַּר רַבִּי יוֹסֵי, אָמַר לוֹ: הַחְזָקַת, בְּנִי, הַחְזָקַת; וּבָא לִפְנֵי רַבִּי חִיָּא, אָמַר: יָגַעְתָּ וּפָתַחְתְּ, יָגֵעַ וְסָתוּם"- בָּבָא בָּתְרָא נט ע"ב)