Is the repetition of the word "I" in a hadith from the act of Satan, or is there no harm in it?

There is no objection to a speaker saying "I am I" if it is not intended for arrogance, showing off, or self-aggrandizement. The Companions said it in the presence of the Prophet, peace and blessings be upon him, and he did not forbid them. Examples include Abu Bakr's saying "I am" in the hadith about who woke up fasting... etc. Similar instances occurred with many Companions and Successors, and none of them condemned another.

As for the hadith of Jabir ibn Abdullah, which states: "I came to the Prophet, peace and blessings be upon him, and knocked on the door. He said: 'Who is it?' So I said: 'I am'," the scholars disliked saying "I am" because it did not provide any benefit that would remove the ambiguity. Rather, the speaker should state his name or describe himself with what he is known by if there is no alternative, such as Umm Hani's saying: "I am Umm Hani'."