March 17

There are no set forms of meditation prescribed in the teachings, no plan, as such, for inner development. The friends are urged -- nay enjoined -- to pray, and they also should meditate, but the manner of doing the latter is left entirely to the individual. The inspiration received through meditation is of a nature that one cannot measure or determine. God can inspire into our minds things that we had no previous knowledge of, if He desires to do so. 
(From a letter dated 25 January 1943 written on behalf of Shoghi Effendi to the believers; The Compilation of Compilations, Vol. II, The Importance of Prayer, Meditation and the Devotional Attitude)