Massekhet Azilut (Hebrew: מסכת אצילות, romanized: māsekheth ʾəṣiluth, lit. 'Mask of Nobility') is an anonymous kabalistic work from the early 14th century. It is the earliest literary product of speculative Kabbala that contains the doctrine of the Four Worlds, a doctrine not contained in the Zohar, as well as that of the concentration of the Divine Being. The Messekhet Atzilut opens with the following passage:
Eliyahu opened, it is written, "The secret of God is for those who fear Him". (Psalms 25:14) This verse refers to the idea that even if a Jew learns Mishnah, Gemara and yet has no awe—for naught does he splash in the great waters [of Kabbala], he toils entirely for nothing. Every one who fears God should actively pursue the hidden aspects [of Torah], which are the essence of wisdom and knowledge, "God's glory is a hidden thing". (Proverbs 25:2) When will you make glory for God? When you are occupied in the hidden aspects of Torah.[citation needed]