Bhavartha Ratnakara Part 9: Sagittarius Ascendant (Dhanur Lagna) | VedAstro
A modern English guide to the classical Vedic astrology text by Sri Ramanujacharya, translated and annotated by B.V. Raman.
Part 9 of 28

Dhanur Lagna
For a person born in Sagittarius Saturn produces good results and confers yoga in his Dasa, if he is in the 5th house.
For a person born in Dhanus, Saturn in the 11th confers yoga; for a person born in other lagnas, Saturn in the 11th does not cause any yoga.
A person born in Sagittarius, with the Sun and Venus in the 9th and Saturn in the 3rd, will enjoy fame and wealth in the course of Sani Dasa.
A person born in Sagittarius with Mars and the Sun in Kumbha and Rahu in Leo, will have a bath in the sea in Rahu Dasa.

Commentary & Analysis by B.V. Raman
A careful reading into the above stanzas seems to bring out one important fact, viz., the lord of the 11th (who is generally declared evil) produces good results if he is in conjunction with a trinal lord or quadrangular lord (who is a natural malefic). For example, on page 26 stanza 1, while dealing with Vrischika Lagna, the author seems to imply that Dhana yoga is caused by the conjunction or mutual aspect of Jupiter and Mercury. Jupiter is no doubt a natural benefic but for Vrischika Lagna he becomes a trinal lord (5th Kendraadhipati), while Mercury is lord of 8th and 11th. Again, in stanza 2 under Vrischika Lagna, Rahu and Venus are said to confer Raja yoga if Budha is in the 7th with Venus and the Sun. Venus as Kendraadhipati becomes evil, while the Sun alone is (temporarily) benefic as owning the 10th.
Again, in stanza 3 under Dhanur Lagna, the author makes it clear that Sun produces good in his Dasa if he is in Kumbha and the Sun and Venus are in the 9th or Simha with Venus as lord of 11th for Dhanur Lagna and his connection with the Sun seems—association with a trinal lord. Venus becomes (somewhat) evil on effects of his eleventh house lordship; his aspect over Saturn cannot be construed as so good as Saturn and Sun are bitter enemies and the Sun and Venus the bitter enemies. Only Saturn and Venus are friends. The conjunction of the Sun (good) and Venus (evil) tends to render the Sun's qualities better and the aspect of Venus also favourable. I may not be quite correct in all my arguments. But this is how I understand the stanzas and I venture to conviction. The author perhaps gives peculiar combinations as my humble experience goes most of them seem to satisfy practical application.