وَعَنْ أَبِي قَتَادَةَ أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ: «إِذَا دَخَلَ أَحَدُكُمُ الْمَسْجِدَ فَلْيَرْكَعْ رَكْعَتَيْنِ قَبْلَ أَنْ يجلس»
Al-Hasan said that ‘Umar b. al-Khattab congregated the people with Ubayy b. Ka‘b as imam and he led them in prayer for twenty nights, but led them in humble supplication only in the second half. When the last ten days came he withdrew and prayed in his house, and the people were saying, “Ubayy has run away.” Abu Dawud transmitted it.
Abu Usayd (RA) — Mishkat al-Masabih #704 (Sahih)