Sheikh Abd al-Aziz ibn Baz رحمه الله mentioned:
The sitting after the taslim in the prescribed prayers is from the most important times, in which the mercy of Allaah descends (upon his slaves). Do not hastily get up, rather seek forgiveness from Allaah, glorify Him, praise Him, and magnify Him.
Ibn Baṭṭal رحمه الله said:
"Whoever has many sins and desires that Allaah remove these sins from him without burdening himself, then let him seize this opportunity and remain seated in his place after the prayer, so that he may take advantage of the supplications from the Angels and their asking forgiveness for him."
Source: Sharh Ibn Battal, vol. 3, pg. 114