He did not pronounce it definitively he only said it that he would or intended to. But He did not is the marriage still valid.
This divorce has not taken place, so long as the husband did not utter the words of divorce, because intention on its own is not enough for divorce to take place.
This is the view of the majority of scholars, as mentioned by al-Haafiz in al-Fath (9/394), and as quoted by Ibn Qudaamah in al-Mughni (7/121) from the majority of scholars. They quoted as evidence for that the hadeeth narrated by al-Bukhaari (2528) and Muslim (327) from Abu Hurayrah (may Allaah be pleased with him) who said: The Messenger of Allaah (peace and blessings of Allaah be upon him) said: “Allaah has forgiven my ummah for whatever crosses their minds, so long as they do not act upon it or speak of it.” Qutaadah – one of the narrators of this hadeeth – said: If it said the words of divorce to himself, without uttering it, it does not mean anything.
Shaykh Ibn Baaz said:
If there is merely the intention of divorce, that does not mean that divorce has taken place. Rather divorce takes place when the words are spoken or written. He quoted as evidence the hadeeth mentioned above. Fataawa Islamiyyah, 3/279.
And Allaah knows best.