Presence within Masjids, worshipping Almighty Allah therein, performing Zikr and reciting Salat upon the Prophet all lead to the descent of Divine mercy:

The Beloved Prophet صَلَّى الـلّٰـهُ عَلَيْهِ وَاٰلِهٖ وَسَلَّم said: ‘The Masjid is the abode of every righteous individual, and he whose abode is the Masjid, Allah grants him assurance of His mercy, pleasure and safely crossing the Sirat bridge, entering the Abode of His pleasure, Paradise.’ (Majma’-uz-Zawa’id, vol. 2, p. 134, Raqm 2026)

It is mentioned in a narration that when a person makes the Masjid an abode for Zikr and Salah, then Allah is pleased with him just as people are pleased upon the return of a lost person. (Sanaan Ibn Majah, vol. 1, p. 438, Raqm 800)

5 Narrations regarding the virtues of the first 10 days of Dhul-Hijjah

1.   He صَلَّى الـلّٰـهُ عَلَيْهِ وَاٰلِهٖ وَسَلَّم said, ‘There is no day more esteemed before Allah Almighty than the 10 days of Dhul-Hijjah nor is any righteous action more beloved to Him than the righteous action of these days. Therefore, make abundant Tahleel (لَاۤاِلٰہَ اِلَّا اللہُ), Takbeer (اَللہُ اَکْبَر) and Tahmeed (اَلْحَمْدُلِلہِ) during these days.’ (Musnad Ahmad, vol. 2, p. 365, Hadith 5447)

2.   He صَلَّى الـلّٰـهُ عَلَيْهِ وَاٰلِهٖ وَسَلَّم said, ‘There is no day more superior before Allah Almighty than the 10 days of Dhul-Hijjah.’ (Ibn-e-Habbaan, vol. 6, p. 62, Hadith 3842)

3.   He صَلَّى الـلّٰـهُ عَلَيْهِ وَاٰلِهٖ وَسَلَّم said, ‘In the days in which Allah Almighty is worshipped, there is no day more beloved than the 10 days of Dhul-Hijjah; the fast of each day (excluding 10 Dhul-Hijjah) is equal to the fast of one year, and standing in each night (including 10 Dhul-Hijjah) is equal to standing in Layla-tul-Qadr.’ (Tirmizi,  vol. 2, p. 192, Hadith 758)

4.   He صَلَّى الـلّٰـهُ عَلَيْهِ وَاٰلِهٖ وَسَلَّم said, ‘There is no day more superior and