In Russia, what is traditionally considered unlucky to shake hands or pass objects across?

In Russian superstition, shaking hands or passing objects across a doorway threshold is traditionally considered unlucky.

The threshold is treated as a symbolic boundary between the inside and outside of a home. Because it marks a transition, people may prefer to step fully inside before greeting someone or exchanging an item rather than complete the action while standing on opposite sides.

This is a folk custom, not a universal rule followed by every Russian speaker. Similar threshold taboos occur in other cultures, where doorways are regarded as vulnerable or spiritually significant spaces.

The belief is sometimes confused with the general practice of removing shoes or greeting guests at the entrance. Its specific feature is the prohibition against conducting the handshake or exchange across the threshold itself.