It does not matter whether it was her bed or anything she was sitting on. If anyone touches it, they will be “unclean” until evening.
“ ‘You will make yourselves “unclean” if you eat these things. If you touch their dead bodies, you will be “unclean” until evening.
Anyone who touches anything she sits on must wash their clothes. They must take a bath. They will be “unclean” until evening.
“ ‘Suppose a man sleeps with that woman. And suppose blood from her monthly period touches him. Then he will be “unclean” for seven days. Any bed he lies on will be “unclean.”
Anything that an ‘unclean’ person touches becomes ‘unclean.’ And anyone who touches it becomes ‘unclean’ until evening.”