A pocket-sized bit of old superstition: dream it on Friday, tell it on Saturday, and it is bound to come true. Two lines, over before you know it, and a nice excuse to ask a child what they dreamed about.
From Mother Goose / Nursery Rhymes (traditional). See the whole collection.
Friday night's dream, on Saturday told,
Is sure to come true, be it never so old.
Public domain. Text from The Real Mother Goose (Blanche Fisher Wright, 1916), via Project Gutenberg. View the source edition