What was the supplication that the Companions used to recite on the 15th of Ramadan during the time of Umar ibn al-Khattab?

Several narrations have been reported concerning the supplication of Qunut. The most famous one is what the Messenger of Allah (peace and blessings be upon him) taught to Al-Hasan ibn Ali: "O Allah, guide me among those whom You have guided..." and this is authentic.

As for the supplication that the Companions habitually recited in the Witr Qunut during the era of Umar ibn Al-Khattab, it involved cursing the disbelievers and supplicating for the Muslims, then reciting: "O Allah, You alone we worship, and to You alone we pray and prostrate..." and its chain of narration is authentic.

Similar supplications were reported from Mu'adh al-Qari and from Umar himself, who used to supplicate: "O Allah, forgive us and the believing men and believing women..." and "O Allah, we seek Your help and Your forgiveness..." Al-Bayhaqi and Ibn al-Mulaqqin authenticated these narrations.

Combining what was reported from the Prophet (peace and blessings be upon him) and what was reported from the Companions is good and commendable, or one may consistently recite one of them, and there is goodness in both.