A Sessional Hymn is a set of troparia (hymns) chanted after each kathisma from the Psalter at Matins which is normally preceded by a small litany. In Greek, these hymns are called "kathisma" (because they follow the Psalm readings of the same name. In Slavonic it is called a sedálen from sediti, "to sit" (Cf. Latin sedere, "to sit"). Hymns with the same name are also used after the Polyeleos, for Saints of Polyeleos or Vigil Rank, and the phrase is also used for the hymns after the third ode of the canon at Matins.
- The Festal Menaion (Tr. Mother Mary and Archimandrite Kallistos Ware, Faber and Faber, London, 1984), p. 553.