"If you don't finish what you think, you can't say what you think, you can't be born without worldly customs." Somebody explain the meaning of this sentence!

Only when you finish what you think in your heart can you say what you think; You can't be born until you have finished the usual things in the world. Only by seeing your true colors can you understand your inner nature. Being able to thoroughly understand the unchangeable truth in the world is enough to talk about birth. [Comment] Buddhists believe that the cognitive function of all sentient beings is illusory, just as people with eye diseases will see life and death. Our hearts cling to the body and all kinds of self-thoughts, so there will be life and death. In fact, the concept of body and "I" is an illusion, and the true face of all living beings is Buddha. If we can realize this, we can transcend the illusory mind and realize our immortal true colors. What is the prevailing way in the world? Is "change" and "empty". No matter how big things are, no matter how small things are, they are constantly changing and will eventually disappear into the invisible. If you don't understand this truth, it's hard to be detached from the world. People want what they like to last for a long time. Therefore, they should stick to these things and not be detached. This is because they don't understand the world. The so-called birth is not to escape into the mountains, but to understand the truth of "change" and "emptiness" in the world, to transcend the world without leaving it.