The most gentle thing

So what is the most gentle thing?

Something that moves slowly, slight in touch and small in appearance. Time is. It moves so slowly that the effect is hardly noticeable. We age. Next, it’s touch is so fine that we can feel it within us, especially tender hearts. Our hearts soften with time. Finally it exist though we cannot see it, touch it, or smell it. Not with our senses, but we know it is present by seeing the changes around us and within. With that said, what do you think is the most gentle being?