Does divorce occur by saying: "I swear by Allah, by divorce, three times that I will not speak to him again"? And does it occur if the person had previously divorced his wife twice and taken her back?

An oath by divorce has the ruling of a conditional divorce. Divorce occurs by it upon breaking the oath. If it is by three [divorces], three divorces occur according to the majority of scholars, and this is the opinion adopted for issuing fatwas. Sheikh al-Islam Ibn Taymiyyah is of the view that if the one swearing the oath intended merely to encourage or prevent something, then its expiation is the expiation of an oath [by God]. This opinion has its weight, and some scholars have permitted adopting it to alleviate hardship.

One must be wary of Satan corrupting relations between relatives, for the ties of kinship between them are too great to be weakened by his plots. Among his means is anger, which the Sunnah (definition) has warned against. In cases of estrangement, reconciliation is advised, and the best of those who are estranged is the one who initiates peace.