Masing authored one novel, Rapanui vabastamine ehk Kajakad jumalate kalmistul (Liberation of Rapa Nui, or Seagulls at the Cemetery of Gods) in the late 1930s, which was published posthumously in 1989.

He was awarded the Righteous Among The Nations by Yad Vashem and the Israeli Supreme Court for his participation during the Holocaust in helping a Jew in Estonia escape capture from 1941 until the end of the war.

The small circle of poets became known as Arbujad ("Soothsayers") and included Heiti Talvik, Betti Alver, Paul Viiding, Mart Raud, Bernard Kangro, August Sang and Kersti Merilaas.

After the German invasion of Estonia in World War II he gave up his teaching post at the university and devoted his time to protecting and salvaging Jewish cultural and religious items.

Masing and his wife Eha helped Levin evade capture by supplying him with food, shelter, clothing and even forged documents, while on occasion lying to the Gestapo about knowledge of Isidor.