What is the correct wording for the Tashahhud in prayer after the death of the Prophet, peace and blessings be upon him, and is it "Peace be upon the Prophet" or "Peace be upon you, O Prophet"?

There are several valid forms of the Tashahhud, and scholars have agreed on the permissibility of each. Most scholars have affirmed the permissibility of greeting the Prophet with the vocative form, "Peace be upon you" (السلام عليك). However, a group of scholars held that the vocative form was permissible during his lifetime, while both the vocative and the absent forms were permissible after his death, citing the hadith of Ibn Mas'ud (may Allah be pleased with him) who said: "When he passed away, we said: 'Peace be upon the Prophet' (السلام على النبي)."

This view was supported by Al-Hafiz Ibn Hajar and Al-Albani, who considered it sound, stating that the Companions would say "Peace be upon the Prophet" after his death, and that Aisha (may Allah be pleased with her) would teach them the Tashahhud with this wording.

Al-Albani held that the matter is broad, and any authentically established form of the Tashahhud suffices. As for the majority of scholars, they adhered to the vocative form which the Prophet (peace be upon him) taught his Companions, making no distinction between his lifetime and his death. They viewed Ibn Mas'ud's statement as his own ijtihad (independent reasoning) and countered it with the hadith of Umar, who taught people the Tashahhud with the vocative form after the Prophet's (peace be upon him) death.