"two rakʿahs that the Messenger of Allāh (ṣallá Allāhu ʿalayhi wa-sallam) never abandoned, whether in secret or openly: two rakʿahs before the morning prayer, and two rakʿahs after the afternoon prayer." It is cited in "al-Irwāʾ" (2/188-189) and the previous one in "Ṣaḥīḥ Abī Dāwūd" (1160). Isḥāq ibn Yūsuf, who is al-Azraq, followed Jaʿfar ibn ʿAwn, but he differed from him in the isnād, saying: from Masʿar, from Ḥabīb ibn Abī Thābit, from Abū al-Ḍuḥā with it. It was narrated by Ibn Abī Shaybah (2/353) and Abū al-ʿAbbās al-Sarrāj in his "Musnad" (folio 132/1). Jaʿfar ibn ʿAwn is trustworthy among the narrators of the two Shaykhs. If he preserved it, then Masʿar had two Shaykhs in it; otherwise, al-Azraq's narration is more authentic. Moreover, Ibn Abī Shaybah narrated from a group of the Salaf that they used to perform these two rakʿahs after the afternoon prayer, among them Abū Burdah ibn Abī Mūsá, Abū al-Shaʿthāʾ, ʿAmr ibn Maymūn, al-Aswad ibn Yazīd, and Abū Wāʾil. He narrated it with an authentic chain from them, and among them Muḥammad ibn al-Muntaṣir and Masrūq as mentioned earlier. As for ʿUmar's punishment of those who performed them, it was one of his ijtihādāt based on blocking the means, as indicated by two narrations mentioned by al-Ḥāfiẓ in "al-Fatḥ" (2/65): one in "Muṣannaf ʿAbd al-Razzāq" (2/431-432), "Musnad Aḥmad" (4/155), and al-Ṭabarānī (5/260), and it was deemed good by al-Haythamī (2/223). The other is also with Aḥmad (4/102), and al-Ṭabarānī in "al-Muʿjam al-Kabīr" (2/58-59), and "al-Awsaṭ" (8848 - according to my numbering)