Bharatiya Jyotihshastra (History of Indian Astronomy), translated by R. V. Vaidya v2.c12.s2.t2.3

v2.c12.s2.t2.3

Because these works were regarded as superhuman, they naturally did not include the description of subjects like observations. There seems to be another very strong reason for this omission. Looking to the conditions of those days when as a rule ‘shorter the works, the easier they were to commit to memory’, such works dealt with only the rules of calculating the motions and places of planets, and they appear to have avoided length by omitting the underlying theory.