Ayesha reported,

When the Prophet ﷺ gave the closing salutation of the prayer, he would not remain seated longer than it took to say, "O Allah, You are Peace, and from You comes peace. Blessed are You, Possessor of majesty and honor."In another narration, "O Possessor of majesty and honor."

Azami 11042

Sahih

عن عائشة قالت

كان النبي ﷺ إذا سلم لم يقعد إلا مقدار ما يقول: اللهم أنت السلام، ومنك السلام، تباركت ذا الجلال والإكرام وفي رواية: يا ذا الجلال والإكرام.

الأعظمي 11042صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Supplications, remembrances, and prayer upon the chosen Prophet ﷺ
Chapter
Supplications of adhan and prayer, and what is related to them
Section
Remembrances after the obligatory prayers and at their conclusions
Numbering
Jami al-Kamil 11042 (2nd edition)
Azami 11042