What is the ruling on one who made a covenant with Allah not to do something, then thought about doing it, but did not do it?

"The covenant of Allah Almighty is equivalent to an oath. Thus, whoever says 'the covenant of Allah' and then breaks it, must offer expiation for an oath, according to Malik and a group of the Salaf, based on the verse: 'And fulfill the covenant of Allah when you have made a covenant, and do not break the oaths after their confirmation while you have made Allah, over you, a guarantor. Indeed, Allah knows what you do' (Surah An-Nahl, 16:91). Some scholars, like Ash-Shafi'i, held that it is not an oath unless intended as such. Mere contemplation of breaking the covenant does not necessitate expiation, as the Prophet, peace and blessings be upon him, said: 'Indeed, Allah Almighty has forgiven my Ummah for whatever they think about, as long as they do not speak of it or act upon it.'"