3 sentences

1. 诸行无常是佛法中的重要教义。

   zhū xíng wú​cháng shì fó​fǎ zhōng de zhòng​yào jiào​yì.

   Impermanence is an important teaching in Buddhism.

   Source: Dong Chinese Dictionary

2. 他早已交代好，一旦无常，丧事从简。

   tā zǎo yǐ jiāo​dài hǎo, yī​dàn wú​cháng, sāng​shì cóng​jiǎn.

   He had already instructed that in the event of his passing, the funeral should be simple.

   Source: Dong Chinese Dictionary

3. 民间传说中，黑白无常是专门勾摄生魂的使者。

   mín​jiān chuán​shuō zhōng, hēi​bái wú​cháng shì zhuān​mén gōu​shè shēng hún de shǐ​zhě.

   In folklore, the Black and White Guards are messengers who capture the souls of the living.

   Source: Dong Chinese Dictionary