I love this episode and it is very emotional.. I really was hoping that Stella can react continuously until the ending though.. This episode is really special and it flows really well into the ending credit with the drawings of Tanjiro's and Nezuko's family.. I cried watching it..
For your question, Tanjiro's father told Tanjiro that the Hanafuda earrings and the Hinokami Kagura(Dance of the Fire God) are their family heirloom that needed to be passed down to the next generation..