Is there a Hadith about placing the right hand on the forehead and supplicating after the prescribed prayer?

It is authentically reported from the Prophet (peace be upon him) that when he finished his prayer, he would seek Allah's forgiveness three times, then say: "O Allah, You are As-Salam (the Source of Peace), and from You comes all peace. Blessed are You, O Possessor of Majesty and Honor." As for placing the right hand on the forehead after the obligatory prayer, there is no basis for it, as stated by Sheikh Ibn Baz (may Allah have mercy on him).