Yoga Rahasya Chapter One verse 89

āsaneṣu yathā na-eva kramasya niyamaḥ kṛtaḥ |
prathama-abhyāsa-asinastadvat prāṇāyāmeṣu sarvataḥ ||

Just as in Āsana practice,
proper procedure should never be given up,
beginners in doing Prāṇāyāma,
should always follow the correct procedure.

āsana - particular posture; sitting, sitting down; seat, place, stool; abiding, dwellingyathā - according asna - no; not; nor, neithereva - thuskrama - sequence; order; series; regular arrangement; succession; progressing step by step; in regular course; gradually, by degreesniyama - observances; restraint of the mind; a rule or precept; obligation; restraining, checking, holding backkṛta - done; made; accomplished; performedprathamā - primary, initial, firstabhyāsa - practiceprāṇāyāma - extending the breath