大般涅槃經義記 8.292

8.292

「汝言何故有退心者」牒第八句。下為辯釋，明有性故不畢竟退。「實無退心」正明無退。「若有退」下，難破有退，成心無退。「以遲得」下，釋成退義，成非永退。以斯准驗，但令一念發心求佛，定得菩提無退滅理。

"You say, why is there a retrogressing mind?": he cites the eighth clause. Below, he analyzes and explains, clarifying that because there is a nature, it does not retrogress ultimately. "Truly there is no retrogressing mind": he directly clarifies that there is no retrogression. From "If there were retrogression..." onward, he interrogates and refutes the presence of retrogression, establishing that the mind has no retrogression. From "Because it is attained slowly..." onward, he explains the meaning of retrogression, establishing that it is not permanent retrogression. Verified by this, if one only has a single thought of aspiration to seek buddhahood, one will definitely attain bodhi, and there is no principle of retrogression and cessation.