"A blind man begging on the roadside passed by a lady and changed a few words on the blind man's sign, so this day a miracle appeared." What is the meaning of concealment?

Spring has come, but I can't see it. \ x0d \ x0d \ In the corner of a busy city, a blind old beggar sat blankly. There are only a few invoices in the enamel washbasin in front of him, and no one seems to pay attention to him. It's a spring afternoon. On weekends, people come and go. They are talking about love and feeding each other, and their faces are full of the breath of spring. In the sun, the beggar's head and shoulders are covered with golden camphor leaves. He touched a piece casually, sniffed it in front of his nose, was intoxicated, sighed a long time and dropped the leaves in his hand. \x0d\ At this moment, a gentleman in different clothes came. Seeing this scene, he went over and squatted down to help the old man find the camphor leaves. The old man thanked him. The gentleman said, "I'm sorry, I'm poor, too." I am a poet. I have no money to send you, but wait, I will come to see you again. " \x0d\ continued to be crowded with people, but the old man could only hear different footsteps. He can tell who is a man, who is a woman, who is in a good mood and who is as depressed as he is. Suddenly, he heard familiar footsteps. Yes, it was the poet who had just left. He put down a simple triangle sign and left in a hurry. \x0d\ It seems that people in the street met a stone in the beggar's place, slowed down and splashed. Raindrop-like coins and snowflake-like bills fall into the blind man's basin. It was a rich afternoon, and the old man put his hands together to express his gratitude, while he waited for the poet to appear again. After a while, the poet miraculously returned. He helped the old man put the money in his bag. The old man couldn't wait to ask, "Poet, you are really something. What did you write on the sign? " The poet said, "Listen, there are only a few words: Spring has come, but I can't see it!" " "