Sahih Muslim | Book 25 | Chapter 8

Narrated by Jabir b. Abdullah
Jabir b. Abdullah reported: I came to Allah's Apostle (may peace be upon him) and called him (with a view to seeking permission), whereupon Allah's Apostle (may peace be upon him) said: Who is it? I said: It is I. Thereupon he (the Holy Prophet) came out saying: It is I, it is I.

Narrated by Jabir b. Abdullah
Jabir b. Abdullah reported: I sought permission from Allah's Messenger (may peace be upon him) to see him. He said: Who is it? I said: It is I. Thereupon Allah's Messenger (may peace be upon him) said: It is I, it is I (these words lead me to no conclusion).

Narrated by Shu'ba
This hadith has been transmitted on the authority of Shu'ba with a slight variation of wording and that is: The Holy Prophet (may peace be upon him) uttered these words: It is I, it is I." in the manner as if he disapproved of this.