Комментарий к Берешит 41:26

שבע שנים ושבע שנים SEVEN YEARS AND SEVEN YEARS —all together they are only seven years (not fourteen); and the reason why the dream was repeated is because the thing is ready to happen as he expressly stated to him afterwards (v. 32) “And for that the dream was doubled etc.” With reference to the seven good years it says (v. 25) “[What He is about to do] God hath declared unto Pharaoh”, because it (that period) was close at hand; whilst in the case of the seven years of famine it states (v. 28) “He hath shown unto Pharaoh” — because this thing was distant and far off (as regards time) the proper word to use in reference to it is “showing”.

The dream being repeated twice is because the thing... Rashi is answering the question: Why did Yoseif interpret that this was one dream? Being that one [dream] was with cows and the other with ears, it surely must be two dreams! Therefore Rashi explains that it was [one dream but was] repeated [because of its imminence].