zhēnkǒng
於地上立針，自天上投纖縷，使入針孔，事之甚難者。以譬人身之難受也。法苑珠林三十一曰：「提謂經云：如有一人在須彌山上以纖縷投之，一人在下持針迎之，中有旋嵐猛風吹縷，難入針孔，人身難受甚過於是。」（萬善同歸集五引文同之）。
A needle's eye: it is as difficult to be reborn as a man as it is to thread a needle on earth by throwing the thread at it from the sky.
pinhole
一針孔 於地上立一針，自天上投一絲纖縷，使入針孔，其事甚難，以此比喻人身之難得。〔法苑珠林卷三十一〕p5477