Sutra 1.20 - tīvra-saṁvegānām-āsannaḥ
1. theevra = acute
2. samvega = desire
3. aasannah = with ease, easiness
This sutra is setting us up for the next sutra by describing to us how desire can help us. Patanjali explains that yogis that have an acute desire will find that this path becomes easier and easier. With consistency of practice, as in all things, it becomes easier to progress on the path. As we move with this strong desire, we will find the path opens up more to us, and we can move along with further ease.