首楞嚴義疏注經 8.295

8.295

修道所斷行相難了，故曰微細。無始俱生，故曰沈惑。疑網消除，故云快然。增進聖位，故云饒益。

What is severed by the path of cultivation is difficult to perceive in its activity and characteristics; hence it is called 'subtle.' Innate from beginningless time, it is called 'sunken delusions.' The net of doubts having been eliminated, he says 'delighted.' Advancing in the noble stages, he says 'benefit.'