MEDEA:What makes me cry with pain
Is the next thing I have to do. I will kill my sons.
No one shall take my children from me.

[ΜΉΔΕΙΑ: ᾤμωξα δ᾿ οἷον ἔργον ἔστ᾿ ἐργαστέον
τοὐντεῦθεν ἡμῖν· τέκνα γὰρ κατακτενῶ
τἄμ᾿· οὔτις ἔστιν ὅστις ἐξαιρήσεται·]

Euripides (485?-406? BC) Greek tragic dramatist

Medea [Μήδεια], l. 791ff (431 BC) [tr. Vellacott (1963)]
    (Source)

This is the first time Medea directly announces her intent; scholars debate whether it's where she actually first thinks of it.

The most interesting divergence in translations here is whether Medea is asserting that nobody can save the children from her plan to kill them, or that nobody will take them from her because she will kill them first. The former seems to me more in keeping with the rest of the passage, but some translators disagree. Though her sons were to have been exiled with her, some scholars believe Medea was concerned that they might be killed (taken from her) once she murdered Glauce, Jason's new wife.

(Source (Greek)). Other translations:

But I with anguish think upon a deed
Of more than common horror, which remains
By me to be accomplish'd: for my Sons
Am I resolved to slay, them from this arm
Shall no man rescue.
[tr. Wodhull (1782)]

But what a deed,
Ay, there my heart is anguish'd, what a deed
Must next be done! My sons -- I'll kill them both,
And who shall save them from me?
[tr. Potter (1814)]

But I am woe for what a deed
Needs must be done: for I shall slay my sons.
No one there is who may deliver them.
[tr. Webster (1868)]

But I shudder at the deed I must do next; for I will slay the children I have borne; there is none shall take them from my toils.
[tr. Coleridge (1891)]

But I bewail the deed such as must next be done by me; for I shall slay my children; there is no one who shall rescue them from me.
[tr. Buckley (1892)]

And wail the deed that yet for me remains
To bring to pass; for I will slay my children,
Yea, mine: no man shall pluck them from mine hand.
[tr. Way (Loeb) (1894)]

I gnash my teeth
Thinking on what a path my feet must tread
Thereafter. I shall lay those children dead --
Mine, whom no hand shall steal from me away!
[tr. Murray (1906)]

Oh, my heart
Cries at the thought of what a deed I must
Do after that. For I must kill my children,
Mine own. There lives not who shall rescue them.
[tr. Lucas; ed. Higham (1938)]

I weep to think of what a deed I have to do
Next after that; for I shall kill my own children.
My children, there is none who can give them safety.
[tr. Warner (1944)]

I moan for the kind of task that I must proceed
To accomplish. For I shall put the children to death --
My children. No one will save them from me.
[tr. Podlecki (1989)]

Ah me, I groan at what a deed I must do next! I shall kill my children: there is no one who can rescue them.
[tr. Kovacs (Loeb) (1994)]

It makes me groan to think what deed I must do net. For I shall kill my own children; no one shall take them from me.
[tr. Davie (1996)]

Ah! How I shudder with fear for the monstrous deed that I must do!
Immediately after the murder of the Princess I will have to murder my own children. No one can save them, now, no one!
[tr. Theodoridis (2004)]

I grieve over the deed I must do
after this. For I shall kill my children.
There is no one who will rescue them.
[tr. Luschnig (2007)]

But the next thing I’ll do fills me with pain --
I’m going to kill my children. There’s no one
can save them now.
[tr. Johnston (2008), l. 940ff]

Now hear what follows: I weep for what I must do; for then I'll kill my children. No one will give relief.
[tr. Kovacs / Kitzinger (2016)]

I have mourned the kind of thing that I need to do
After this: For I will kill my children.
There is no one who will save them.
[tr. @sentantiq (2020)]

But then
I'm miserable about what I must do.
I have to kill my children; no one
will take them from my hands.
[tr. Ewans (2022)]

I grieve at the deed I must do next; for I will slay my own children. No one will take them from me!
[tr. Coleridge / Ceragioli / Nagy / Hour25]

Ah me, I groan at what a deed I must do next. I will kill my children: there is no one who can rescue them.
[tr. Kovacs / Zhang / Rogak]