Musar zu Dewarim 28:42

We may simply answer this by saying that all the moon asked for was to retain its size, implying that the size of the sun could be increased. I have explained Deut. 28,43: הגר אשר בקרבך יעלה עליך מעלה מעלה ואתה תרד מטה מטה, "The stranger in your midst will keep rising higher and higher above you, whereas you will sink lower and lower" in a similar vein.