After learning that feet are considered unclean and insulting in India, it can be surprising to see a Hindu bending down to touch someone’s feet with their hand. Why are they doing that?
Touching feet is one of the forms of pranam (there are others, ranging from the namaste/namaskar gesture of palms together to bowing with forehead touching the floor). You might even hear someone say, “Pranam!” as a greeting, especially to their guru.
There is a saying, “Every time you bow, you receive a blessing” which comes from the fact that the person whose feet are being touched raises the right hand in a gesture of blessing, often saying something like, “Ayushman Bhava,” which means, “May you live a long life.”
Foot touching is not done despite feet being considered unclean — it’s done because feet are generally considered unclean. It means that the person has walked this earth longer than you and gained such wisdom that you can benefit even from the dust their feet have picked up along the way.