Shama-il Tirmidhi Chapter 002, Hadith Number 004 (018).

Ebrahim bin Muhammad (Radhiallahu Anhu), who is the grandson of Ali (Radhiallahu anhu said: "Whenever Ali (Radhiallahu Anhu) used to describe the noble attributes of Rasullullah (Sallallahu Alaihi wasallam), he used to mentioned the complete hadith. He also used to say that the Seal of Prophethood was between his shoulders, and Rasullullah (Sallallahu alaihi wasallam) was the seal of all prophets".

Commentary.
This hadith has been explained in the first chapter (hadith number eight). Here it is referred to briefly. Because of the Seal of Prophethood, this hadith is mentioned specially here.