俱舍論疏 7.99

7.99

論「增長因故說為養因」，《正理論》云「言養因者，能長彼故，猶如樹根水所沃潤。欲知五因力用不同，應觀五喻：生因如母生子，依因如弟子依師，立因如地持物，持因如食持命，養因如水潤樹根。」

The treatise says: "Because it causes growth, it is called the nourishing cause." The Nyāyānusāra says: "As for the nourishing cause: because it can foster its growth, just as tree roots are moistened by water. If one wishes to know the different powers and functions of the five causes, one should observe five analogies: the generating cause is like a mother giving birth to a child; the supporting cause is like a student relying on a teacher; the establishing cause is like the earth sustaining objects; the maintaining cause is like food maintaining life; and the nourishing cause is like water moistening tree roots."