Shaikh Dhunun Misri (Allah have mercy on him) said,
There are three signs of sincerity,
1. The doer of action equally disregards the praise and censure of mankind
2. He doesn’t consider his actions to be worthy of acceptance by Allah
3. He doesn’t demand retribution for his actions in this world or in hereafter.
Mujama as Sulook, volume 1, page 371