גָּ֘ד֤וֹל יְהוָ֣ה וּמְהֻלָּ֣ל מְאֹ֑ד בְּעִ֥יר אֱ֝לֹהֵ֗ינוּ הַר־קָדְשֽׁוֹ׃
Rashi on Psalms
in the city of our God In the future, when He builds His city, He will be great and praised because of it.
Metzudat David on Psalms
In the city of our God – that is to say that when He causes His Presence to rest in Jerusalem, His holy mountain. Then He will be great and very much praised in the mouths of all.