說無垢稱經疏 3.188

3.188

贊曰：此即第三，結答詞由卑躬請退。我時不報，故言默也。不能識解此所說解，名無辨也。

The Commentary states: This is the third part: concluding the reply with the reason, humbly asking to decline. At that time I did not respond, hence it says 'remained silent.' Being unable to understand and explain what had been expounded is called 'lacking eloquence.'