The Supreme Personality of Godhead is already in the core of everyone's heart. Isvarah sarva-bhutanam hrd-dese 'rjuna tisthati (BG 18.61). Logically, therefore, it was not at all difficult for Lord Visnu to enter Hiranyakasipu's body

Expressions researched:
"The Supreme Personality of Godhead is already in the core of everyone's heart. Īśvaraḥ sarva-bhūtānāṁ hṛd-deśe 'rjuna tiṣṭhati" |"Logically, therefore, it was not at all difficult for Lord Viṣṇu to enter Hiraṇyakaśipu's body"

Srimad-Bhagavatam

SB Canto 8

The Supreme Personality of Godhead is already in the core of everyone's heart. Īśvaraḥ sarva-bhūtānāṁ hṛd-deśe 'rjuna tiṣṭhati (BG 18.61). Logically, therefore, it was not at all difficult for Lord Viṣṇu to enter Hiraṇyakaśipu's body. The word vivigna-cetāḥ, "very anxious," is significant.

SB 8.19.10, Translation and Purport

Lord Vāmanadeva continued: O King of the demons, after Lord Viṣṇu made this decision, He entered the body of His enemy Hiraṇyakaśipu, who was running after Him with great force. In a subtle body inconceivable to Hiraṇyakaśipu, Lord Viṣṇu, who was in great anxiety, entered Hiraṇyakaśipu's nostril along with his breath.

The Supreme Personality of Godhead is already in the core of everyone's heart. Īśvaraḥ sarva-bhūtānāṁ hṛd-deśe 'rjuna tiṣṭhati (BG 18.61). Logically, therefore, it was not at all difficult for Lord Viṣṇu to enter Hiraṇyakaśipu's body. The word vivigna-cetāḥ, "very anxious," is significant. It is not that Lord Viṣṇu was afraid of Hiraṇyakaśipu; rather, because of compassion, Lord Viṣṇu was in anxiety about how to act for his welfare.