Where is the source of 'Umar's supplication in the opening of the prayer?

The questioner : 'Umar's supplication in the opening of the prayer.

The Shaykh : What follows it, whether it reaches us or not, is not transmitted as marfu' in the two Sahihs, neither in al-Bukhari nor in Muslim. It is This is what was transmitted as marfu', not in al-Bukhari nor in Muslim. However, 'Umar used to recite it aloud, may Allah be pleased with him, to teach the people. So some scholars preferred this over the hadith of Abu Hurayrah, but there is a point of consideration in that, because the hadith of Abu Hurayrah is explicitly and clearly marfu', whereas regarding the hadith of 'Umar, one might say that 'Umar did not affirm it and recite it aloud to teach the people unless he had it as marfu', especially since he mentioned it in a specific order. Ibn al-Qayyim, may Allah have mercy on him, preferred it in *Zad al-Ma'ad* from ten angles, but all of them are angles in which there is a point of consideration regarding their strength.