Abdul-Razzaq reported that the Prophet ﷺ said, "Whoever prays the night prayer and the dawn prayer in congregation, it is as if he stood in prayer the entire night."Abdul-Rahman said, "Whoever prays the night prayer in congregation, it is as if he stood in prayer for half the night, and whoever prays the dawn prayer in congregation, it is as if he stood in prayer the entire night."
حدثنا عبد الرحمن حدثنا سفيان وعبد الرزاق قالا حدثنا سفيان عن عثمان بن حكيم عن عبد الرحمن بن أبي عمرة
عبد الرزاق عن النبي ﷺ قال من صلى صلاة العشاء والصبح في جماعة فهو كقيام ليلة وقال عبد الرحمن من صلى العشاء في جماعة فهو كقيام نصف ليلة ومن صلى الصبح في جماعة فهو كقيام ليلة
Its isnad is sahih. Uthman bin Hakeem bin Abbad bin Hunayf Ansari is a trustworthy and reliable narrator (thabit).As for his statement "and Abdul-Razzaq said, Sufyan narrated to us," we have established it from H, while in C and K it reads, "they both said, Sufyan narrated to us," which is not correct. For Abdul-Rahman bin Mahdi had already said before this, "Sufyan narrated to us," so there is no sense in repeating the narration jointly with Abdul-Razzaq afterward.