What is the ruling on committing a sin with the intention of repenting, while guaranteeing life and repentance, and is this considered a mockery of the inviolable limits of Allah?

It is not permissible to commit a sin with the intention of repenting, because this is from the deception of Satan. A person does not know if he will live long enough to repent, or if he will be granted the ability to repent. "The procrastinator bases the matter on something that is not certain, which is survival, for he might not survive, and even if he does, he might not be able to abandon it tomorrow just as he cannot abandon it today." The desire that a person reinforces through habit multiplies and becomes stronger. The example of the procrastinator is like someone who needs to uproot a strong tree and says, "I will postpone it for a year," knowing that the longer the tree remains, the more firmly rooted it becomes, and the longer he lives, the weaker he becomes.