Yoga Sutras 1.9
Patanjali, explained by Swami Vivekananda
शब्दज्ञानानुपाती वस्तुशून्यो विकल्पः ॥
śabdajñānānupātī vastuśūnyo vikalpaḥ
Verbal delusion follows from words having no (corresponding) reality.
In plain words: Some thoughts come from words that point to nothing real. The teacher says we often jump to conclusions from words without thinking, and we should ask why some news is making us angry or upset.
Swami Vivekananda explains
There is another class of Vrittis called Vikalpa. A word is uttered, and we do not wait to consider its meaning; we jump to a conclusion immediately. It is the sign of weakness of the Chitta. Now you can understand the theory of restraint. The weaker the man, the less he has of restraint. Examine yourselves always by that test. When you are going to be angry or miserable, reason it out how it is that some news that has come to you is throwing your mind into Vrittis.