In the letter to Silberstein, of January 30, 1875, Freud informed Eduard that he had written, an obituary. The occasion was, allegedly, that, the journal founded by the three, and later four, of us ... has passed peacefully into the keeping of the Lord.
Further, Freud bizarrely stated, It was I who delivered the death blow, it had been ailing for a long time and I took pity on its suffering. I gave it life and I have taken its life away, so blessed be my name, for ever and ever, Amen.  *
What is remarkable is not the question (allegedly) of a journal ending its existence, but Freud's obsessive references to death-related subjects ,even when writing about issues having nothing to do with death.
Thus, unusually for a message related to the closing of a "journal", Freud talks about obituary, about delivering the death blow, and about taking life, a statement more suitable for the description of infanticide.
Whether the quote referred to a journal or the killing of a newborn is anyone's guess,
Assuming, for argument’s sake, that the quote relates to killing, we could rewrite it as follows:
It was I who delivered the death blow ... I gave it life and I have taken its life away, so blessed be my name, for ever and ever, Amen.
In a footnote referring to the above quote, the editor added the reference: After Job 1:21.  *
Thus, as the editor intimated, Freud was paraphrasing the biblical quote as follows:
And he said, “Naked I came from my mother's womb, and naked shall I return. The Lord gave, and the Lord has taken away; blessed be the name of the Lord."
Both Freud's quote, and the biblical quote, deal with birth and death, but in Freud's quote, it is Freud, rather than the Lord, who gives and takes life, thus making it sound like an act of infanticide.
A case in point: Freud was nineteen at the time, and, no doubt, taking no precautions. In fact, throughout his life, Freud was always against any means of contraception. How many  of his patients he impregnated is not known. Most certainly, more than once, he impregnated his daughters.
And, if Freud was describing taking the life of a newborn child, Freud wouldn't be the first Herod. Throughout human history, infanticide was a common practice as a means of disposal of unwanted offspring.
* Freud, Sigmund, The Letters of Sigmund Freud to Eduard Silberstein, 1871-1881, (1989, p. 86).