SB 10.1.59
drstva samatvam tac chaureh
satye caiva vyavasthitim
kamsas tusta-mana rajan
prahasann idam abravit
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
My dear King Pariksit, when Kamsa saw that Vasudeva, being situated in truthfulness, was completely equipoised in giving him the child, he was very happy. Therefore, with a smiling face, he spoke as follows.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The word samatvam is very significant in this verse. Samatvam refers to one who is always equipoised, unaffected by either happiness or distress. Vasudeva was so steadily equipoised that he did not seem in the least agitated when delivering his first-born child into the hands of Kamsa to be killed. In Bhagavad-gita (2.56) it is said, duhkhesv anudvigna-manah sukhesu vigata-sprhah. In the material world, one should not be very eager to be happy, nor should one be very much disturbed by material distress. Lord Krsna advised Arjuna:
matra-sparsas tu kaunteya
sitosna-sukha-duhkha-dah
agamapayino ’nityas
tams titiksasva bharata
“O son of Kunti, the nonpermanent appearance of happiness and distress, and their disappearance in due course, are like the appearance and disappearance of winter and summer seasons. They arise from sense perception, O scion of Bharata, and one must learn to tolerate them without being disturbed.” (Bg. 2.14) The self-realized soul is never disturbed by so-called distress or happiness, and this is especially true of an exalted devotee like Vasudeva, who showed this by his practical example. Vasudeva was not at all disturbed when delivering his first child to Kamsa to be killed.