Sunan an-Nasa'i, Volume 2, Book 14, Hadith 1399 (DarusSalam)

It was narrated from Aws bin Aws Ath-Thaqafi that : The Messenger of Allah said: "Whoever washes (ghassala) and performs ghusl, and comes early to the masjid and sits near the imam, is attentive and does not engage in idle talk, for every step he takes he will have (the reward of) a year's worth of good deeds, its fasting and Qiyam prayer."

أَخْبَرَنَا مَحْمُودُ بْنُ خَالِدٍ، قَالَ حَدَّثَنِي عُمَرُ بْنُ عَبْدِ الْوَاحِدِ، قَالَ سَمِعْتُ يَحْيَى بْنَ الْحَارِثِ، يُحَدِّثُ عَنْ أَبِي الأَشْعَثِ الصَّنْعَانِيِّ، عَنْ أَوْسِ بْنِ أَوْسٍ الثَّقَفِيِّ، عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم قَالَ ‏ "‏ مَنْ غَسَّلَ وَاغْتَسَلَ وَابْتَكَرَ وَغَدَا وَدَنَا مِنَ الإِمَامِ وَأَنْصَتَ ثُمَّ لَمْ يَلْغُ كَانَ لَهُ بِكُلِّ خُطْوَةٍ كَأَجْرِ سَنَةٍ صِيَامِهَا وَقِيَامِهَا ‏" ‏ ‏.‏

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also referenced under: Book 14, Hadith 1409 (In-Book)