tasya (तस्य, tasya) = its (referring to nirodha parinama (निरोधपरिणाम, nirodha-pariṇāma))
prashanta (प्रशान्त, praśānta) = tranquil; undisturbed
vahita (वाहिता, vāhitā) = flow
sanskara (संस्कार, saṁskāra) = impressions resulting from repeated actions; acquired habits

Each thought creates a mental impression and the creation of new connections between the brain’s neurons, thus making previous thoughts easier to recall and more familiar. The more often a thought occurs, the more anchored its neuronal path becomes. Patanjali refers to such impressions as samskaras. Even the end point of thought, which is contemplation, creates a mental impression, thus making it ever easier for us to attain this state.