The Dao De Jing, also known as the Tao Teh Ching, is a short written work with a huge influence on Chinese thought, society, and the traditional Chinese sciences. Attributed to Laozi (aka Lao Tse, Lao Tzu, Lao Zi, et cetera) and about 3000 years old, the Dao De Jing is, like the 道 Dao (aka Tao) itself, almost impossible to describe accurately. You could call it the earliest surviving written work which talks about the Dao, or the Way.
It's important to remember that at the time the Dao De Jing was written, there was no such thing as "Daoism". Organized religion, temples, monasteries and state influence all came later.
One of many stories told about the genesis of the work goes like this: Laozi was a sage who became fed up with the artificiality of human society. He rode off on a donkey but was stopped by a border guard who recognized him and begged him to stay. Laozi refused. The guard asked him to at least write down his teachings so that future generations could benefit. Laozi relented, sat down and dashed off a quick 81 verses which we now know as the Dao De Jing. Then he got back on his donkey (sitting backwards, perhaps) and rode off over the mountains - some say to India, where he had the opportunity to teach a young man who later became the Buddha (yes that Buddha), then on to Persia, where he influenced the founders of Zorastrianism, and so on, seeding enlightenment wherever he went.
There are many many translations of and commentaries on the Dao De Jing. Today's selection is from Cheng-Man Ching's commentaries, titled Lao-Tzu: My Words Are Very Easy To Understand and translated by Tam Gibbs. Cheng Man Ching is also well known as a taijiquan teacher in the U.S. and Taiwan.
Yield, and become whole.
Bend, and become straight.
Hollow out, and become filled.
Exhaust, and become renewed.
Small amounts are obtainable;
Large amounts are confusing.
Therefore the Sage embraces the Oneness of the Tao
And becomes a guide for the whole world.
He does not focus on himself and so is brilliant.
He does not seek self-justification and so becomes his own evidence.
He does not make claims and hence is given the credit.
He does not compete with anyone, and hence no one in the world can compete with him.
How can that which the ancients expressed as "yield, and become whole" be meaningless?
If wholly sincere, you will return to them.