Every blade of grass has its angel that bends over it and whispers, “Grow, grow.”

The Talmud (AD 200-500) Collection of Jewish rabbinical writings

Midrash Rabba, Bereshit 10:6

Usually attributed to the Talmud, but actually from a Midrash.Alt. trans.:

• "R. Shimon said: There is not a single herb but has a mazal [constellation] in the heavens which strikes it and says, 'Grow!'" [tr. Rabbi Ruth Adar]
• "Said Rabbi Simon: 'Every single blade of grass has a corresponding 'mazal' in the sky which hits it and tells it to grow." [Source]