Sunan an-Nasa'i 1381
سنن النسائي#1381SahihIt was narrated from Aws bin Aws that:The Prophet (ﷺ) said: "Whoever washes (Ghassala) and performs Ghusl, comes early to the Masjid and sits near the Imam, and does not engage in idle talk, he will have for every step he takes (the reward of) a year's worth of good deeds, fasting it and praying Qiyam during it
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiIsnaad Sahih
In-book reference: 14:18