A hadith—[if authentic]—(1) states:
“I wish that I had seen…”
or he said:
“May Allah have mercy upon my successors.”
They asked, “Who are your successors, O Messenger of Allah?”
He replied, “Those who revive my Sunnah and teach it to the people.” (2)
If this is authentically established as a statement of the Prophet—may Allah bless him and grant him peace—it constitutes evidence concerning the matter at issue. Even if it is not his statement, it still shows that, in the milieu of whoever fabricated it, the term “successor” was customarily applied to someone who succeeded another, even if that other person had not appointed him as his successor. Thus, if someone takes another’s place and fulfills his role in certain matters, he is his successor in that respect.