The Ace of Swords is a card of clarity, ideas and control/self-discipline. It often comes up when we have "a-ha" moments, but it also shows the need to removes undesired energies from our life. The ace of swords is also associated ith the mind, intellect and communication. The Nine of Pentacles is the card of abundance, of comfort and security, but primarily, it is the card of self-sufficiency and independence. We feel good for what we have achieved and we enjoy the fruits of our efforts. The combination of the Ace of Swords and the Nine of Pentacles is about handling practical matters in the best possible way.
To understand the elemental relationships between the cards, we should always take into account their actual meaning. The elements of the cards are Air (Ace of Swords) and Earth (Nine of Pentacles). A neutral combination in which the Earth card often tries to oppose the Air Card by absorbing its energy, through a gravitational pull. However, these two have a common thread: the element of discipline and control. That's why we should expect positive results when this combination comes up in a reading.