Vrtrasura requested Indra to release the thunderbolt immediately, and he prepared himself by fixing his mind at the lotus feet of Krsna. A devotee is always ready to give up his material body, which is described as the rope of material attachment

Expressions researched:
"Vṛtrāsura requested Indra to release the thunderbolt immediately, and he prepared himself by fixing his mind at the lotus feet of Kṛṣṇa. A devotee is always ready to give up his material body, which is described herein as grāmya-pāśa, the rope of material attachment"

Srimad-Bhagavatam

SB Canto 6

Vṛtrāsura requested Indra to release the thunderbolt immediately, and he prepared himself by fixing his mind at the lotus feet of Kṛṣṇa. A devotee is always ready to give up his material body, which is described herein as grāmya-pāśa, the rope of material attachment. The body is not at all good; it is simply a cause of bondage to the material world. Unfortunately, even though the body is destined for destruction, fools and rascals invest all their faith in the body and are never eager to return home, back to Godhead.

SB 6.11.21, Translation and Purport

By the force of your thunderbolt, I shall be freed of material bondage and shall give up this body and this world of material desires. Fixing my mind upon the lotus feet of Lord Saṅkarṣaṇa, I shall attain the destination of such great sages as Nārada Muni, just as Lord Saṅkarṣaṇa has said.

The words ahaṁ samādhāya manaḥ indicate that the most important duty at the time of death is to concentrate one's mind. If one can fix his mind on the lotus feet of Kṛṣṇa, Viṣṇu, Saṅkarṣaṇa or any Viṣṇu mūrti, his life will be successful. To be killed while fixing his mind at the lotus feet of Saṅkarṣaṇa, Vṛtrāsura asked Indra to release his vajra, or thunderbolt. He was destined to be killed by the thunderbolt given by Lord Viṣṇu; there was no question of its being baffled. Therefore Vṛtrāsura requested Indra to release the thunderbolt immediately, and he prepared himself by fixing his mind at the lotus feet of Kṛṣṇa. A devotee is always ready to give up his material body, which is described herein as grāmya-pāśa, the rope of material attachment. The body is not at all good; it is simply a cause of bondage to the material world. Unfortunately, even though the body is destined for destruction, fools and rascals invest all their faith in the body and are never eager to return home, back to Godhead.