Salawat: The Heaviest Deed on the Day of Judgment

Hawzah News Agency- Imam Baqir or Imam Sadiq (pbut) said:

أَثْقَلُ مَا يُوضَعُ فِي الْمِيزَانِ يَوْمَ الْقِيَامَةِ الصَّلَاةُ عَلَى مُحَمَّدٍ وَأَهْلِ بَيْتِهِ.

The heaviest thing placed on the scale on the Day of Resurrection is sending blessings (salawat) upon Muhammad and his household.

Wasa'il al-Shi'ah, Vol. 7, p. 193, No. 9102