When Gandhari saw, she saw that he was not fully naked, so she regretted, "O my dear son, I asked you to come before me naked. Why you have got this...?" "No, Krsna advised." Then she began to smile, that "My attempt is failure." So Krsna knew it

Expressions researched:
"My attempt is failure" |"No, Krsna advised" |"O my dear son, I asked you to come before me naked. Why you have got this" |"So Krsna knew it" |"Then she began to smile, that" |"when Gandhari saw, she saw that he was not fully naked, so she regretted"

Notes from the compiler: Story: Gandhari, Duryodhana, Krsna

Srimad-Bhagavatam Lectures

He asked him, "Where you are going?" "I am going to see my mother." "How is that? You are going naked? At least you have some langota(?). This is not good." So he took the instruction of Kṛṣṇa and covered the private part with a langota. And when Gāndhārī saw, she saw that he was not fully naked, so she regretted, "O my dear son, I asked you to come before me naked. Why you have got this...?" "No, Kṛṣṇa advised." Then she began to smile, that "My attempt is failure." So Kṛṣṇa knew it, that part which was covered, that was not turned iron.

Lecture on SB 1.7.13-14 -- Vrndavana, September 12, 1976:

Everyone was determined, "I must kill." Duryodhana was determined to kill Bhīma, and Bhīma was determined to kill. So when they did not listen to the instruction of Baladeva, then Baladeva left the place. He went to Dvārakā, back. Of course, Kṛṣṇa was there, because Kṛṣṇa was to give hint to Bhīma how to kill Duryodhana. So Duryodhana, by the blessings of his mother, his whole body became iron-like solid. So by beating by the Bhīma, it was not easy. So the story is that Gāndhārī, the mother of Duryodhana, she was great chaste woman. Because her husband was blind, she used to remain as blind woman covering the eyes. But she had some power. Chaste woman, anyone who sticks to the regulative principles, he gets a power, spiritual or material. He gets power. A brahmacārī gets power if he follows brahmacarya. Everyone, if we follow the prescribed rules and regulations, automatically you become powerful.

So Gāndhārī had some power. So her eldest son, Duryodhana, was advised to see the mother naked. She advised, "My dear son, tomorrow morning when you come to offer your obeisances to me, you come naked. I shall see you and you will be solidified just like iron." So he was going naked and Kṛṣṇa saw. So He asked him, "Where you are going?" "I am going to see my mother." "How is that? You are going naked? At least you have some langota(?). This is not good." So he took the instruction of Kṛṣṇa and covered the private part with a langota. And when Gāndhārī saw, she saw that he was not fully naked, so she regretted, "O my dear son, I asked you to come before me naked. Why you have got this...?" "No, Kṛṣṇa advised." Then she began to smile, that "My attempt is failure." So Kṛṣṇa knew it, that part which was covered, that was not turned iron. The other parts turned into iron on account of seeing by Gāndhārī. So in this fight Kṛṣṇa hinted Bhīma that "You strike here. That part is not ironized." Although it is against the regulative principle to strike the opponent party below this waist, Kṛṣṇa advised that "Unless you transgress this law, you cannot kill him." So he was stroken below the waist, and he was not killed, but his waist was broken. Therefore it is said vṛkodarāviddha-gadābhimarśa. Then he died.