If you're the one doing the quote, you can wrap the quote in <large><large> tags, twice for even bigger, per below:
Original quote:
Zincht:
the quoted text is too small to read
One <large>QUOTE</large> tag:
Zincht:
the quoted text is too small to read
Two <large><large>QUOTE</large></large> tags:
Zincht:
the quoted text is too small to read
But if you're reading anyone else's quote, or if you're looking for an even easier way, just use the zoom function in your browser of choice to make all text bigger. :>