To comprehend the meaning of Graha Arudha, we need to understand the meaning of Arudha or Pada. The word Arudha or Pada means mounted one or something that manifests in the physical world and we can perceive it with our five senses. It also means a symbol that represents something so that we can have meaning out of it.
For instance, to convey our happiness through a text message, we may use an emoji such as a smiley face. The smiley face serves as a Pada or manifestation of our happiness. The person we are communicating with will understand that we are expressing our happiness through the use of this emoji.
Just as we have the Arudha of Bhavas (house) similarly we have the Arudha of Grahas, which shows the manifested Intelligence that natives apply to various subject matter. It also shows the manifested Intelligence of other people in the life of the native. The Arudha of Lagna is called Arudha Lagna and that of Bhava is called Bhav Pada.
Maharishi Parashara teaches Graha Arudha and Bhava Arudha in the same chapter.
My attempt to explain Bhav Arudha and Graha Arudha via the game of cricket :
For example in the game of cricket when we see the scoreboard board we can find out what is the situation of the game at a particular time and in the end we can evaluate who won the game.
So the scoreboard is the Arudha or Pada (Mounted Symbol of the cricket match) which tells us about the status of the match.
Someone who has not seen the live match can give us great insight into the circumstances of the match just by looking at the scorecard of the match.
Similarly, when there is an appeal for an Out, the umpire raises his index finger in the air to declare the batsman out in favor of the fielders otherwise he does nothing. He has to express his decision in a certain manner so that all can understand and can make meaning out of it.
The Umpire acting and behaving in a certain manner to the appeal of the fielding side is the Graha Arudha Pada of the Lagna lord (Intelligence)/ and or 5th lord (decision making) of the umpire. Because he is manifesting his decision by doing so.
Late Shri C.S Patel in his beautiful book on ‘Arudha systems of predictions ‘ has curled out various verses from classics on Bhava and Grha Arudhas. One verse from Bhrigu Nadi, from the book for the readers.
“If Chandra Arudha is occupied or aspected by Benefic Planets (Venus, Jupiter, Moon [8th Tithi Shukla Paksha to 8th Tithi Krishna Paksha] and uninflected Mercury) then the maternal family of the native is prosperous and maternal uncle is wise and loveable man.
This information may enlighten many on the Arudha System of Jyotish, who think that it is only taught by Maharshi Jaimini. Infect DevKerlam (Chandra Kala Nadi, a renowned classic) also has many verses explaining results using Arudhas of bhavas/grahas.
In addition to this Maharshi Parasara in Brihat Parashara Hora Shastra and Maharishi Jaimini in Jaimini Sutra have taught Arudha in great detail.