וַיִּ֤בֶן הָעִיר֙ מִסָּבִ֔יב מִן־הַמִּלּ֖וֹא וְעַד־הַסָּבִ֑יב וְיוֹאָ֕ב יְחַיֶּ֖ה אֶת־שְׁאָ֥ר הָעִֽיר׃
און ער האָט פֿאַרבױט די שטאָט רונד אַרום, פֿון מִלוֹא ביז רונד אַרום. און יוֹאָבֿ האָט פֿאַרריכט דעם רעשט פֿון דער שטאָט.
Rashi
and the work was improved A similar instance is (Neh. 3:34): “Will they revive the stones” of Ezra. Also, above (I Chron. 11:8): “and Joab sustained.’
Radak
And he healed By way of borrowing [from its original meaning], it used the term, healing, [to mean] building a destroyed building. And likewise (Nehemiah 4:1), "that healing had come to the walls of Jerusalem"; and likewise (I Chronicles 11:8), "and Yoav resuscitated the rest of the city."