Kala (কাল / Time in cosmic sense) Sarpa (সর্প / serpent) = Serpent of Time.
Searching the classics for the existence of Kaal Sarpa Yoga: –
Whenever a problem arises, we consult the classics of Vedic astrology, but in this case the problem is that we don’t find anything regarding Kal Sarpa Yoga in Brihat Parasara Hora Sastra, Jaiminisutram, Brihat Jatakam, Uttar Kalamrita, Phaladeepika, Jatak Parijat, Sarbartha Chintamani, Bhabartharatnakar, Jatakabharanam, Sanketnidhi, Bhabakutuhalam, Manasagari Paddhati, even the modern Astro books like, jataktatwa etc. don’t speak anything about this Kal Sarpa Yoga.
Pundit Shree P.S. Sastri discussed about Kal Sarpa Yoga in the Astrological magazine published from Bangalore in the volume of December 1965, October 1987 & September 1994. While discussing about KSY, Mr. Sastri quoted a sloka, but didn’t mention about its root. However, he admitted that classics don’t talk KSY. The sloka he quoted is as under:-
“Agre rähuù ante ketu sarbe madhyagatä grahäù,
yogam kälasarpäkhyam nåpa çasya binäçanam”.
The meaning is quite clear. If Rahu is at front & Ketu is at last while all other planets are in between, then this combination is called Kal Sarpa Yoga & results into death of king of destruction of grains.
It is clear that the above mentioned sloka has nothing to do with personal astrology (Jatak Jyotish) & is related to Mundane Astrology (Rashtriya Jyotish).