soft to the touch: of fine, luxurious clothing
This is the plain, physical meaning of the word: something that feels soft. In the New Testament it describes clothing, the fine and costly garments of people who live in comfort.
In the Gospels Jesus uses it to make a contrast. People who wear soft clothing live in the palaces of kings, not in the wilderness, so John the Baptist in his rough camel-hair was clearly not that kind of man. The word here is not an insult; it simply marks luxury and ease. A faint edge of social comment is present, since soft clothes belong to those who do not labor, but the sense is fundamentally literal.
The wider Greek world used the same word for soft beds, soft ground, soft skin, and gentle, mild things of every kind. The clothing sense in the Gospels sits squarely inside that ordinary range.