Just as flour, sugar and oil are kept at home, and on arrival of some guests, sweet dishes are prepared, served and eaten.
Just as beautiful dresses, pearl necklace and gold jewellery are in possession but are worn on special occasions like marriage and are shown to others.
Just as valuable pearls and jewels are kept in the shop, but shopkeeper shows them to the customer to sell and earn profit.
Similarly Gurbani is written in a book form, it is bound and preserved. But when the Sikhs of Guru assemble in a congregation, that book is read and heard and it helps one attach the mind in the holy feet of the Lord.