One bathes upon seeing water, and plucks leaves upon seeing the tulsi plant.

This couplet points out a common human tendency. Just as we instinctively use water for bathing when we see it, and pluck leaves from a Tulsi plant when we encounter it, people often act out of self-interest. It suggests that humans tend to exploit resources or situations for their own immediate benefit, without much thought for the long-term impact or the inherent value of what they are using. It's a subtle commentary on how we often take things for granted and use them primarily for our own convenience or gain.