This is the 4055th most frequent Russian word.
москвой
"Москвой" is the instrumental case of "Москва" (Moscow), meaning "by/with Moscow" or "Moscow" in contexts requiring this grammatical case.
Here, 'Москвы' (of Moscow) is in the genitive case, showing possession or relation.
Я всегда мечтал о путешествии в город с названием Москва и о времени, когда я смогу гулять по улицам Москвы.
I have always dreamed of traveling to the city named Moscow and about the time when I can walk along the streets of Moscow.
'Москвой' (with Moscow) is in the instrumental case, used here to indicate the manner or location in relation to the subject.
Между нами и Москвой стоят сотни километров.
Between us and Moscow, there are hundreds of kilometers.
'Москвой' (with Moscow) is in the instrumental case, describing the association or context of the action taking place with Moscow.