See a pin and pick it up, all the day you'll have good luck
A proverb extolling the virtue of thrift.
'See a pin and pick it up, all the day you'll have good luck' is an old proverbial phrase and is included in collections of early nursery rhymes in its full form:
See a pin and pick it up, all the day you'll have good luck;
See a pin and let it lie, bad luck you'll have all day
...although it is difficult to imagine children singing this in the playground with much conviction.
It covers the same ground as 'take care of the pence and the pounds will take care of themselves', i.e. an encouragement to believe that thrift in small things will bring a reward.
On 2nd January 1667 Samuel Pepys made this entry in his diary:
This day, at White Hall, I overheard Sir W. [William] Coventry propose to the King his ordering of some particular thing in the Wardrobe, which was of no great value; but yet, as much as it was, it was of profit to the King and saving to his purse. The King answered to it with great indifferency, as a thing that it was no great matter whether it was done or no. Sir W. Coventry answered: "I see your Majesty do not remember the old English proverb, ‘He that will not stoop for a pin, will never be worth a pound.’"
This shows that the idea, if not the precise current wording, was a known to be an old proverb by the 17th century.