兀然無事坐、春夾草自生

兀然 wù rán “quietly” (can also mean “dazed”, “bewildered”, “suddenly”, “unexpectedly”, or “abruptly”)
無事 wú shì “nothing happening”
坐 zuò “sitting”
春 chūn “spring”
來 lái “come, arrive, happen, occur”
草 cǎo “grass”
自 zì “oneself”
生 shēng “live, grow”

From the “Zen Sand” (aka “Zenrin-kushū”, “Zen Phrase Book”, 禪林句集).
See the very nice Terebess page here: https://terebess.hu/zen/kushu.html