俱舍論疏 1.41

1.41

論「由彼生死至所以喻泥」，釋頌泥義。三界五趣是生死處，業雜愛水其類於泥，處之即沈溺、出之即難。可漸下名沈，沒故稱溺。九十五種不能離故，難可得出，處泥必沈沒、小力不能出，二義同故，以喻於泥。

The treatise says: "Because that saṃsāra [...] therefore it is compared to mire"—this explains the meaning of "mire" in the verse. The three realms and five destinies are the place of saṃsāra; karma mingled with the water of craving is comparable to mire. Being in it, one sinks and drowns; getting out of it is difficult. Sinking down gradually is called sinking; being submerged is called drowning. Because the ninety-five kinds [of heterodox paths] cannot escape it, it is difficult to get out. Being in the mire, one must sink and drown, and with small strength one cannot get out; because these two meanings are identical, it is compared to mire.