I (Vasudeva) promise that when she (Devaki) gives birth to the sons from whom your fear has arisen, I shall deliver them all unto your hands - SB 10.1.54

Expressions researched:
"I promise that when she gives birth to the sons from whom your fear has arisen, I shall deliver them all unto your hands"

Srimad-Bhagavatam

SB Canto 10.1 to 10.13

Vasudeva said: O best of the sober, you have nothing to fear from your sister Devakī because of what you have heard from the unseen omen. The cause of death will be her sons. Therefore I promise that when she gives birth to the sons from whom your fear has arisen, I shall deliver them all unto your hands.

SB 10.1.54, Translation and Purport

Vasudeva said: O best of the sober, you have nothing to fear from your sister Devakī because of what you have heard from the unseen omen. The cause of death will be her sons. Therefore I promise that when she gives birth to the sons from whom your fear has arisen, I shall deliver them all unto your hands.

Kaṁsa feared Devakī's existence because after her eighth pregnancy she would give birth to a son who would kill him. Vasudeva, therefore, to assure his brother-in-law the utmost safety, promised to bring him all the sons. He would not wait for the eighth son, but from the very beginning would deliver to the hands of Kaṁsa all the sons to which Devakī would give birth. This was the most liberal proposition offered by Vasudeva to Kaṁsa.