Ruling on one who omits the middle tashahhud due to forgetfulness

The questioner, Ala al-Din Yusuf Ibrahim from al-Madimur in Sudan, says: Peace be upon you, and Allah’s mercy and blessings. And after that: My greetings to you, the presenter of the program, and to our program, or rather the school of millions, *Nur 'ala al-Darb* (Light on the Path). I am truly impressed by it, and I suggest that you increase the duration of the program. I hope you will pose this question to the honorable shaykhs: I was praying the odd-numbered prayer (witr). After the second rak'ah, I stood up in forgetfulness, knowing that I had not sat down. So I completed four rak'ahs, then prostrated for forgetfulness before the taslim. Was this valid, or was it obligatory for me to repeat it? Guide us to the truth, and may Allah guide you.
Answer: What you did, O questioner, is in accordance with the Sunnah. It is established from the Prophet (peace and blessings be upon him) that in one of the two afternoon prayers, either the Zuhr or the 'Asr, he stood up for the third rak'ah without sitting for the first tashahhud. Rather, he stood up for the third, and the people stood up with him. When he finished the prayer and the people were waiting for his taslim, he said takbir and prostrated two prostrations for forgetfulness, then said taslim, in place of the sitting he had left, which is the sitting of the first tashahhud. This is what is prescribed when a person stands up in forgetfulness from the first tashahhud and does not sit in the Zuhr, or in the 'Asr, or in the Maghrib, or in the 'Isha'. He does not go back, but continues. If he stands up and settles into standing, he continues. This is the best for him; he does not go back, but continues in his prayer. When he finishes his prayer and the time for taslim arrives, he says takbir and prostrates two prostrations, just like his prostration in the prayer, exactly the same. Then he says taslim after that. And in the prostration for forgetfulness, he says what he says in the prostration of the prayer: "Subhan Rabbi al-A'la" (Glory be to my Lord, the Most High), "Subhan Rabbi al-A'la," "Subhanaka Allahumma Rabbana wa bihamdika, Allahumma ighfir li" (Glory be to You, O Allah, our Lord, and with Your praise, O Allah, forgive me). He supplicates with whatever good supplications he wishes, then says taslim. The point is that in the prostration of the prayer, the prostration for forgetfulness, the prostration of recitation, and the prostration of gratitude, one says what is said in the prostration of the prayer, of tasbih and supplication. This is what is prescribed. Yes.