Sending peace on the Prophet immediately after saying Taslim of an obligatory Salah

Q: What is the ruling on saying thrice immediately after Salah (Prayer): "O Allah! Send Your Mercy and Blessings on our Master Muhammad, Your servant and Messenger", then saying: "Glory to your Lord, the Lord of Honor and Power. (He is free) from what they ascribe (to Him). And Peace on the Messengers. And praise to Allah, the Lord and Cherisher of the Worlds", then shaking hands with one another? Please answer me, may Allah reward you.

A: First: Invoking Allah’s Mercy and Blessings on the Prophet (peace be upon him) is prescribed by Shari‘ah (Islamic law) and even made obligatory by Allah. Moreover, it is of great merit and entails great reward. However, it will be out of place to say it immediately after an obligatory Salah as the Prophet (peace be upon him) is not authentically reported to have done so. Undoubtedly, good lies in following the practice of the Prophet (peace be upon him).Second: It should not be a usually adopted practice to shake hands after concluding obligatory Salah as it is not one of the Sunan (supererogatory acts of worship following the example of the Prophet) of Salah. (Part No. 5; Page No. 427) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.