Sunan Abu Dawud
1287
Daif+3

Narrated Mu'adh ibn Anas al-Juhani: The Prophet (ﷺ) said: If anyone sits in his place of prayer when he finishes the dawn prayer till he prays the two rak'ahs of the forenoon, saying nothing but what is good, his sins will be forgiven even if they are more than the foam of the sea

DaifAl-Albani
DaifMuhammad Muhyi Al-Din Abdul Hamid