Is what was uttered by the husband considered a first divorce, and what is the ruling in the two mentioned cases, knowing that he reconsidered and regretted what he said?

Your statement to your wife, "If you do such and such, you will be divorced," can be interpreted in two ways:

1. A promise of divorce: In this case, nothing is binding upon you even if your wife does that, as it is merely an non-binding promise. 2. Conditional divorce (ta'liq al-talaq): If you intended to make her divorce conditional upon the action, then the majority of scholars hold that the divorce occurs as soon as she performs the action upon which it was conditioned. You cannot retract this condition according to the majority. However, Shaykh al-Islam Ibn Taymiyyah holds that retraction is possible.

Regarding making divorce conditional upon your wife speaking with her colleague, the matter depends on your intention. If you intended that your wife should not intentionally speak with her, then there is no violation (hanth) upon you if she speaks to her unintentionally. If you did not have a specific intention, then the divorce occurs according to the majority if she speaks to her, unless she was unaware that she was the one sworn upon, in which case there is further detail and disagreement.