ANSWER:

You make a commitment not to commit the sin while repenting, however it’s not done verbally and it is just a firm intention of the heart. 

https://youtu.be/2-SB5SccnIs

I watched your video on offering Kafarah if you go back to a sin after ‘telling Allah’ you won’t go back to it. Sheikh whenever we repent, isn’t it a condition that we make a commitment when making the Tawbah to Allah, that we won’t go back to the sin. But sometimes we may end up doing that sin again,& after watching ur video I got the impression that we have to offer Kafarah also