What is a key quality for every spiritual aspirant?

You experience joy and misery through the ear. Therefore, avoiding the cruel arrows of harsh words, one should use words that are sweet, pleasant and soft. With that softness, add the sweetness of truth. To make the words soft, if falsehood is added, it would only clear the way for some more misery. Hence, a spiritual aspirant should use very soft, sweet, true and pleasant words. The mind of such an aspirant is Mathura, their heart is Dwaraka and their body is Kashi. Such persons can be recognized by their good qualities themselves.