✅Answer: Please pay attention to the following narration:

عَنْ أَبِی عَبْدِ اللَّهِ فِی حَدِیثٍ قَالَ الطَّلَاقُ عَلَی غَیْرِ السُّنَّةِ بَاطِلٌ

📚Al-Kafi, Vol. 6, p. 58

Translation: Imam Sadiq (peace be upon him) said in a hadith: 'A divorce that is not according to the Sunnah is void.'

✅In the verses of the Quran and the narrations of the Ahl al-Bayt (peace be upon them), conditions have been set for divorce, and if these conditions are deficient, according to the narrations, including the above hadith, the divorce is void.

✅Some general principles of divorce are:

1- The woman not being in a state of menstruation at the time of divorce:

عَنِ الْحَلَبِیِّ قَالَ سَأَلْتُ أَبَا عَبْدِ اللَّهِ عَنْ رَجُلٍ طَلَّقَ امْرَأَتَهُ وَ هِیَ حَائِضٌ فَقَالَ الطَّلَاقُ لِغَیْرِ السُّنَّةِ بَاطِلٌ

📚Al-Kafi, Vol. 6, p. 58

Translation: Halabi said: 'I asked Imam Sadiq (peace be upon him) about a man who divorces his wife while she is menstruating.' The Imam said: 'A divorce not according to the Sunnah is void.'

2- The woman being in a state of purity in which no intercourse has taken place:

زُرَارَةَ عَنِ الْیَسَعِ قَالَ سَمِعْتُ أَبَا جَعْفَرٍیَقُولُ لَا طَلَاقَ إِلَّا عَلَی السُّنَّةِ وَ لَا طَلَاقَ عَلَی سُنَّةٍ إِلَّا عَلَی طُهْرٍ مِنْ غَیْرِ جِمَاعٍ

📚Al-Kafi, Vol. 6, p. 62

Translation: Yasa' said: 'I heard Imam Baqir (peace be upon him) say: 'There is no divorce except according to the Sunnah, and there is no divorce according to the Sunnah except in a state of purity without intercourse.'

3- The intention and will to divorce:

عَنْ أَبِی عَبْدِ اللَّهِ قَالَ لَا طَلَاقَ إِلَّا لِمَنْ أَرَادَ الطَّلَاقَ

📚Al-Tahdhib, Vol. 8, p. 51

Translation: Imam Sadiq (peace be upon him) said: 'There is no divorce except for someone who has the intention and will to divorce.'

4- Taking two just witnesses for the divorce:

عَنْ أَبِی جَعْفَرٍ فِی حَدِیثٍ قَالَ وَ إِنْ طَلَّقَهَا لِلْعِدَّةِ بِغَیْرِ شَاهِدَیْ عَدْلٍ فَلَیْسَ طَلَاقُهُ بِطَلَاقٍ وَ لَا یَجُوزُ فِیهِ شَهَادَةُ النِّسَاءِ

📚Al-Kafi, Vol. 6, p. 61

Translation: Imam Baqir (peace be upon him) said in a hadith: 'If a man divorces his wife without two just witnesses according to the 'iddah' (waiting period), his divorce is not a divorce, and in (divorce) the testimony of women is not permissible.'

✅Also, pay attention to the following narration:

عَنْ أَحْمَدَ بْنِ مُحَمَّدِ بْنِ أَبِی نَصْرٍ قَالَ سَأَلْتُ أَبَا الْحَسَنِ عَنْ رَجُلٍ طَلَّقَ امْرَأَتَهُ عَلَی طُهْرٍ مِنْ غَیْرِ جِمَاعٍ وَ أَشْهَدَ الْیَوْمَ رَجُلًا ثُمَّ مَکَثَ خَمْسَةَ أَیَّامٍ ثُمَّ أَشْهَدَ آخَرَ فَقَالَ إِنَّمَا أُمِرَ أَنْ یُشْهَدَا جَمِیعاً

📚Al-Kafi, Vol. 6, p. 71

Translation: Ahmad said: 'I asked Imam Abu al-Hasan (peace be upon him): 'A man divorces his wife in a state of purity without intercourse and on the same day takes one witness for the divorce, and then waits for five days and takes another witness (is it valid?)' The Imam said: 'Indeed, they have been commanded that both witnesses should be present together (and be witnesses to the divorce).'

✅According to the above narrations, a single witness alone and taking two just witnesses separately affects the validity of the divorce, and all conditions, including the simultaneous presence of two just witnesses, must be observed.

✅In case of knowledge and awareness that the divorce was performed against the Sunnah, necessary caution must be exercised in temporary and permanent marriage with the divorced woman with incomplete conditions. Pay attention to the following important hadith:

عَنْ أَبِی عَبْدِ اللَّهِ أَنَّهُ قَالَ إِیَّاکُمْ وَ ذَوَاتِ الْأَزْوَاجِ الْمُطَلَّقَاتِ عَلَی غَیْرِ السُّنَّةِ

📚Al-Kafi, Vol. 5, p. 423

Translation: Imam Sadiq (peace be upon him) said: 'Strictly avoid married women who have been divorced against the Sunnah.'

✅Due to the importance of the matter of marriage, sufficient caution must be exercised regarding temporary and permanent marriage with women who have been divorced against the Sunnah, especially absentee divorces that have become common today and have very important conditions, because Imam Sadiq (peace be upon him) said: 'The matter of the private parts is serious, and the child comes from it,' and he said: 'Indeed, marriage is more deserving and more deserving of caution, and it is the matter of the private parts, and the child comes from it.'

📚Al-Tahdhib, Vol. 7, p. 470

📚Man La Yahduruhu al-Faqih, Vol. 3, p. 84