Saying 'Talaq' without the Intention of Divorce
The ruling in the light of the Hadith is that if any person says the word, "Talaq," then the intention is not considered, as the word "Talaq" is used only for separation between the couple. It has got no other usage and sense. Thus, if the husband used the word "Talaq," without any intention, even then divorce occurs. As given in Sunan Abu Dawood, Vol. 1, Pg. No. 298, Hadith No: 1875:
Translation of Hadith: It has been narrated on the authority of Hadhrat Abu Hurairah (May Allah be well pleased with him) that the Holy Prophet (Sallallahu alaihi wa sallam) said: There are 3 things in which seriousness is also seriousness and joking is also seriousness: Nikah (Marriage), Talaq, Raja'at (i.e. Uniting after the first revocable divorce). As given in Durre Mukhtaar, Vol. 2, Pg. No. 465.
Using ambiguous/unclear words
If someone says: 'Go to your mother' or such words and does not actually divorce his wife, then these words are about the future and mean a promise. The ruling of the Shariah is that a promise to divorce does not constitute a divorce.
In this case, a divorce is not affected on the wife. As given in Bahjatul Mushtaaq Fi Ahkamit Talaq, Pg. No. 13. Author: Mufti Hafidh Syed Ziauddin Naqshbandi Qadri, Professor, Islamic Law, Jamia Nizamia