Is it permissible for a person to forbid something upon himself if it is without recompense, or if it wastes time, such that he gains a benefit from this prohibition?

It is understood from the verses of Surat At-Tahrim (The Prohibition) that one is forbidden from prohibiting what is lawful for oneself, and that whoever prohibits something permissible then wishes to do it, must offer expiation for an oath. This is based on Allah’s admonishment of His Prophet Muhammad, peace and blessings be upon him, when he forbade himself from drinking honey, as stated in Allah's words: ﴿O Prophet! Why do you prohibit what Allah has made lawful for you, seeking to please your wives? And Allah is Forgiving, Merciful. Allah has already ordained for you the dissolution of your oaths. And Allah is your Protector, and He is the All-Knower, the All-Wise.﴾ At-Tahrim /1-2.