Be precise with one's language
Insisted on the speech that comes from his mouth. He was precise in what he said. He took care with the words that come from his mouth, carefully phrasing his statements.
("And the Scripture does not always precisely follow its language, sometimes saying 'by his hand' and sometimes 'about him'" - Rashi on Nehemiah 3:2, and likewise: "Rather, a person must be precise with his language and know what the mouth utters" - Agnon / Up to Here, 118)
Translation
Expression (Hebrew)
דִּקְדֵּק בִּלְשׁוֹנוֹ
Definition (Hebrew)
הִקְפִּיד עַל הַדִּבּוּר הַיּוֹצֵא מִפִּיו.דִּיֵּק בְּמָה שֶׁאָמַר. הִקְפִּיד עַל הַדְּבָרִים הַיּוֹצְאִים מִפִּיו, נִסֵּחַ בִּזְהִירוּת אֶת דְּבָרָיו.
("וְהַמִּקְרָא לֹא דִּקְדֵּק בִּלְשׁוֹנוֹ פְּעָמִים שֶׁהוּא אוֹמֵר עַל יָדוֹ וּפְעָמִים שֶׁהוּא אוֹמֵר עָלָיו"- רָשִׁ"י נְחֶמְיָה ג ב, וְכֵן:"אֶלָּא שֶׁצָּרִיךְ אָדָם לְדַקְדֵּק בִּלְשׁוֹנוֹ וּלְיֶדַע מָה הַפֶּה מוֹצִיא"- עַגְנוֹן/ עַד הֵנָּה, 118)