Patañjali's Yogasūtra I.42

Yogasūtra I.42 - tatra śabda-artha-jñāna-vikalpaiḥ saṁkīrṇā savitarkā-samāpattiḥ |

This Samāpatti is only the first step and is not entirely pure.

Here in this [first stage of absorption called] Savitarka-Samāpatti, understanding of a gross object of focus is distorted and mixed up with its name, concept and imagination.

In the first stage, which is called Savitarka-samäpatti, the object of focus is gross, that is, an object which can be grasped by the senses. Also, there is a mixture of ideas, based on past experiences, what we have read, what we have heard and our imagination and memory. So, even though absorption is possible, our clarity is not yet complete and pure. The patterns of our perception, which are based on memory and latent impressions, interfere at this stage.