Yoga Sutra 1.19

भवप्रत्ययो विदेहप्रकृतिलयानाम् ॥१९॥

bhava-pratyayo videha-prakṛti-layānām ॥19॥

1. bhava: objective existence, becoming
2. pratyayah: content of mind, cognition
3. bhavapratyayah: birth and past karma is the cause
4. videha: disembodied yogis
5. prakṛti: subtlest material cause, nature
6. layānām: dissolved, merged into
7. prakṛtilayānām: the yogis who are merged into prakriti

The videha and prakritilaya yogis get birth as the cause of asamprajnata samadhi. (This is bhavapratyaya asamprajnata samadhi.)

OR

Some who have attained higher levels (videhas) or know unmanifest nature (prakritilayas), are drawn into birth in this world by their remaining latent impressions of their previous births (Karmas), and more naturally come to these states of samadhi.

Past merits needed for asamprajnata samadhi - Samadhi can be attained through faith, by courage, memory, a great deal of perseverance and a higher form of intelligence. And often it takes many years of intense practice to attain samadhi.

But as per this verse, many people attain samadhi without any practice and effort. It happens naturally because at the time of birth they get all the traces of their past Karma. So they pick up from there where they left in their previous life. Saint Jnaneshwar, Ramana Maharshi of Arunachala, Swami Vivekananda were few examples from the recent past.

In this sutra, Patanjali says, there are two types of yogis. Those who are disembodied and those who are merged into Prakriti, can attain asamprajnata samadhi right from birth. They don´t need to practice dharana, dhyana, or vitarka, vichara, etc.

References

• Four Chapters on Freedom by Swami Satyananda Saraswati, published in 1976.