LALLACHARYA SISHYADHI VRUDDHI TANTRA 700 AD
Asuro yadi maayayaa yutho niyatho athigrastheethi they
mantham ganithena katham sa labhyathe grahakrutha parva vinaa kathanchana
If you are of the opinion that an artifical demon is always the cause of an eclipse by swallowing,
then how is it that an eclipse can be determined by means of calculations.
Moreover why is then not an eclipse occur on a day other than the day of new or full moon
(Sishyadhi vruddhi Tantra 20-22)