For the theological use (as equivalent to Grk. οὐσία), usually referencing the Father, see Taylor, DSS (CSCO 577) p. xxv. and E. G. Mathews and J. P. Amar, St. Ephrem the Syrian: Selected Prose Works: Commentary on Genesis, Commentary on Exodus, Homily on Our Lord, Letter to Publius (Fathers of the Church; Washington, DC: The Catholic University of America Press, 1994), 274 fn.5 as cited by S.H. Griffith in his translation of Narsai's on Abraham#1, in A. Butts et al., eds., NARSAI: THE HOMILIES VOLUME I (Peeters, 2024): p. 26 n.5.