A neighbor of Mālik ibn Dinār said:
"One night I heard him saying to himself,
'That's how you should be!'
"The next morning I told him, 'There was no one home with you, so who did you say that to?' He said,
'Myself asked me for some bread, it insisted so I restrained it from eating for three days, then I found a dry piece of bread, when I was about to eat it I said, wait I will get soft bread so it [his self] said, I am contented with this. So I said,
"That's how you should be!"
Disciplining the Soul p.97 | al-Ḥāfiẓ Abū'l-Faraj ibn al-Jawzī | Dār as-Sunnah Publishers
Some of the righteous predecessors would desire a sweet treat, and so they would promise themselves to eat it. If they prayed the night prayer they would allow themselves this reward.