The following is a translation from an Arabic Q&A:
Question: What statements uttered by the husband leads to divorce. I.e. if the husbands says to his wife to leave his house, is this equivalent to a divorce or is it only when the word ‘talaq’ is used?
Answer: The expression used for divorce is the word ‘divorce and its derivatives’ such as when the man says to his wife ‘You are divorced (anti taaliq) or ‘I have divorced you (tallaqtuki) and the like from the derivatives of the word ‘divorce’. If he said this then the divorce will take place in its correct form according to the Sharee’ah rules. In this situation the intention is not considered. If the divorce was pronounced with seriousness or jokingly the divorce will take place. The Messenger (saw) said: Three things should be taken as serious and their joking is taken as serious and they are: marriage, divorce and Raj’ah (taking the wife back after the revocable divorce [Talaq raj’i]) Reported by Tirmizi and he said it is Hasan ghareeb.
If he uses other expressions in front of his wife which can mean divorce but without using the word ‘divorce’. Then in this case the intention is considered for the divorce to take place. If he says to his wife: Go back to your family’ or ‘I have no guardianship over you’ or ‘you are not tied down i.e. free’ and so on and so forth. Then he is asked as to what he meant by these expressions. If he says divorce then divorce will take place and if he says I meant something else then this is not considered divorce.
The evidence: It has been narrated by ‘Aisha (ra) that 'When the daughter of Al-Jaun was brought to Allah's Apostle (as his bride) and he went near her, she said, ‘I seek refuge with Allah from you.’ He said, ‘You have sought refuge with The Great; return to your family.’ Reported by Bukhari. Here it is divorce because the messenger (saw) intended divorce when he said: go back to your family’
And in the Hadeeth regarding when Ka’b b. Malik stayed behind from jihad, he said: When a period of forty out of fifty nights had passed, the messenger of the Messenger of Allah (saw) approached me and said: ‘The Messenger of Allah (saw) commands you to distance yourself from your wife.’ I said: ‘Should I divorce her, or what must I do?’ He responded: ‘No, distance yourself from her and do not approach her. So I said to her: ‘Go back to your family’. Here it is not divorce because Ka’b did not intend divorce by the expression: ‘go back to your family’.
In short, if the pronouncement includes the word divorce and its derivatives then the divorce takes place in its correct form whether he was serious or joking, the intention is not relevant here.
However, if the wording does not explicitly mention divorce but rather by indication or the like then his reason or intention is considered and whether divorce takes place or not depends on this.