Al-Matalib al-'Aliyah 445 — Making up missed prayers

It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever forgets a prayer and does not remember it until he is praying (another) prayer with the imam, let him complete that prayer of his with the imam; then, when he has finished that prayer, let him (first) pray the prayer he had forgotten, and then let him also repeat the prayer that he performed with the imam."
Imam Abu Ya'la recorded it in his Musnad (5621); there is criticism of its attribution to the Prophet (marfu') because of the narrator Sa'id bin Abd al-Rahman al-Jumahi in its chain, whereas this narration is established from Sayyiduna Ibn Umar (may Allah be pleased with them both) as his own statement (mawquf) with an authentic chain.