Sagittarius is the sign of expanding knowledge. It is the spirit of exploration, and that is why, as the natural ruler of the 9th house it is about foreign travels, higher education, and spiritual studies. All of these are areas where consciousness is expanded outwards. Why outwards, because Sagittarius is a fire sign. Fire does not actually mean the element, it implies a force, a force that radiates outwards. Thus all the fire signs are “radiating outwards”. In Sagittarius this takes place on a philosophical level.
When the Moon hits Sagittarius its time for expanding your ideas, your business, your relations, your generosity. Sagittarius is about moving out of boundaries, or expanding boundaries. Thus it is during the time of Sagittarius that we have an opportunity to move out of our old habit cycles. Where Sagittarius is in your chart, is the place where you will be gifted with knowledge and understanding. It is also the place you will gain insight into through traveling.
Since Jupiter is the god of gifts, it is also a time to pay attention to sudden gifts that might come to you. If they do, this a boon sign, and should be taken advantage of.