Yōga Sūtra 1.42

तत्र शब्दार्थज्ञानविकल्पैः सङ्कीर्णा सवितर्का समापत्तिः।

tatra śabdārthajñānavikalpaiḥ saṅkīrṇā savitarkā samāpattiḥ।

[तत्र शब्द अर्थ ज्ञान विकल्पैः सङ्कीर्णा सवितर्का समापत्तिः।
tatra = in this stage; śabda = words; artha = its meaning; jñāna = its knowledge; vikalpaiḥ = its imagination; saṅkīrṇā = mixed with each other; savitarkā = with right-logic; samāpattiḥ = results in equilibrium state;]

In this stage, meaning of the word, it's knowledge, and it's imagination mixed with each other results in "savitarka-samadi", equilibrium state with right-logic.

This is the first stage of equilibrium state where still mind is engaged in activity, trying to validate the experience through logic. Though word, its meaning, its knowledge, and its imagination are all mixed, there is union in the ability of the mind to grasp, mind itself acting as grasper, and graped topic. Hence it is called an equilibrium state.