Does a triple divorce occur by threatening one's wife with it if the son touches the phone again, with the intention that this oath is only for one day, knowing that the son is one and a half years old and the intention was to scare the child from excessive attachment to the phone? And what is the solution to revoke this oath?

If you intended fright and intimidation with this oath, you cannot retract it.

As for restricting your oath to a specific time, this depends on your intention when you swore it. If you made the prohibition absolute, then it is not permissible for you to restrict it to a single day thereafter.

If the child touched the phone and you punished your wife with the punishment you intended by your words: "I will teach you a lesson," then you have fulfilled your oath and your divorce does not occur. However, if you did not punish her with the intended punishment, then your triple divorce occurs, according to what is deemed authoritative by us.

As for the view of Ibn Taymiyyah, your divorce does not occur by your breaking of the oath, but you are liable for an expiation for an oath.