金光明經文句記 2.145

2.145

初、釋前三句。欲知智在說，故以聽經而為般若。又聽經發智慧故。心有染故，用不自在；今既清淨，能成解脫。

First, he explains the preceding three sentences. To know that wisdom lies in expounding, he takes listening to the sūtra as prajñā. Also, it is because listening to the sūtra generates wisdom. Because the mind has defilement, its function lacks ease; now that it is purified, it can accomplish liberation.