My response, if it wasn't so sad, might be funny. (The border between tears of sadness and tears of joy is often narrow).
Catherine Jones, my great great grandmother, promised her brother Isaac, on his deathbed, that if she should ever have a son she would name him Isaac after him, so that his name would live on after his death.
Catherine had a son who she duly named Isaac. Unfortunately Isaac died nine months after he was born, so the name wouldn't live on through him. A second son named Isaac also died in infancy, and a third son was born also baptised Isaac.
Isaac #3 was desperately ill with little hope of his survival when Catherine's fourth son was born. Having promised her departed brother a son who would keep his name alive, she named the fourth son Isaac (in anticipation of Isaac #3's death).
Against the odds Isaac #3 survived. So there were now two living son's called Isaac in the family.
Isaac #4 was the one who carried my great granduncle's name. I don't remember him, but I do have a slight recollection of Isaac #3 – who I knew as a child as Hen dewyrth (Old Uncle) David.
The sadness of keeping a deathbed promise through the death of two children, and the desperation to keep that promise so much, that one anticipates the death of a living child is heart wrenching.
But, having said that, at a distance, there is a humorous irony in the story too.