Is fasting on Mondays and Thursdays the Sunnah, or is fasting two days a week sufficient to follow the Sunnah of the Messenger (peace be upon him)?

The best fasting is the fast of David (peace be upon him), who used to fast one day and break his fast one day. The minimum that should be maintained is fasting three days of every month, based on the Prophet's (peace and blessings be upon him) saying: "Three days from every month, and Ramadan to Ramadan, this is like fasting the whole year." Fasting on Mondays and Thursdays is recommended because deeds are presented to Allah Almighty on these days. If a Muslim fasts on other days (except for Friday alone or Saturday alone), it is a good deed for which he will be rewarded, even if it does not have the virtue of Monday and Thursday. It falls under the general virtue of voluntary fasting, based on the Prophet's (peace and blessings be upon him) saying: "Hold fast to fasting, for there is nothing equal to it."