It is a Part of the Sunnah to Call Witnesses to the Reunion

Question :

I became extremely angry with my wife due to a minor thing which she had done. After my anger left, my wife said that I had divorced her once during my anger. So I sat down and recollected, had I pronounced this divorce? Then I remembered it, but I am not completely sure about it and I did not have the intention to divorce my wife, but the words slipped from my mouth when I was in the grip of anger without my intending it; and since I am sure that my wife would not lie in what she said, I took her back at once, but I did not call witnesses to the fact that I had taken her back; in fact, I said to her: "I have taken you back and intimate relations have been restored between us, as they were before."

Now a period of time has passed since the occurrence of what I mentioned, but I remain with doubts and skepticism. So I request Your Eminence to deliver a legal verdict, has divorce occurred in the circumstances I described? And if divorce has taken place, then what is the ruling on my taking her back in this way, and what is incumbent upon me, bearing in mind that it was a revocable divorce, but the duration of the waiting period was over?

Answer:

Your taking back your wife is correct since it occurred during the waiting period and the Sunnah is and that two witnesses testify to it, according to the Words of Allah, Most Glorified:
"Then when they are about to attain their term appointed, either take them back in a good manner or part with them in a goodThe Book of Divorce manner. And take as witness two just persons from among you (Muslims). And establish the testimony for Allah."

The scholars have cited this noble Verse as evidence that it is prescribed to call witnesses for divorce and Ar-Raj'ah. But it is more prudent for you to count this divorce and to consider that it has taken place. That is, according to what you said in the question regarding what you remembered, and your trust in your wife's words, in accordance with the words of the Prophet ﷺ:
"Whoever avoided the unclear matters has kept his religion and his honor blameless.

And his ﷺ saying:
"Leave what makes you doubt for what does not make you doubt.

Source:
Ibn Baz
Fatawa Islamiyah, Vol. 6 Pages 68-69