this commentary was written "for the benefit of [my] son[s]", which can either refer to gnyan phul byung ba/ as Sa chen's "spiritual son", or to his biological sons, slob dpon bsod nams rtse mo/ (1142–1182) and rje btsun grags pa rgyal mtshan/ (1147–1216) Stearns 2001 (pp. 22f.)