This convenience writer tells the reader that rest is needed for dreams,
She recommends sleep, and also more prolonged rest periods.
The rest is necessary for the imagination to flourish, and for the mind and body to create and recognize possibility.
Note that the writer has cited her source, the 1886 Practical Recipes for Making Ice Cream, and has chosen to place her text inside a drawing of an ice cream churn.
The churn suggests both rest and action, and presents an allegory.
When an ice cream batter is chilled [rested] and then churned, it creates a rich dessert [experience].
When the Mind is Left at Rest
for a number of hours, or days or weeks,
it throws up a fantastical layer well known as Dreaming
which is simply Experience very rich in Possibility