SB 10.4.2
te tu turnam upavrajya
devakya garbha-janma tat
acakhyur bhoja-rajaya
yad udvignah pratiksate
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Thereafter, all the watchmen very quickly approached King Kamsa, the ruler of the Bhoja dynasty, and submitted the news of the birth of Devaki’s child. Kamsa, who had awaited this news very anxiously, immediately took action.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Kamsa was very anxiously waiting because of the prophecy that the eighth child of Devaki would kill him. This time, naturally, he was awake and waiting, and when the watchmen approached him, he immediately took action to kill the child.