Jami` at-Tirmidhi 2433

An-Nadr bin Anas bin Malik narrated from his father who said:"I asked the Prophet (s.a.w) to intercede for me on the Day of Judgement. He said: 'I am the one to do so.'" [He said:] "I said: 'O Messenger of Allah! Then where shall I seek you?' He said: 'Seek me, the first time you should seek me is on the Sirat.'" [He said:] "I said: 'If I do not meet you upon the Sirat?' He said: 'Then seek me at the Mizan.' I said:'And if I do not meet you at the Mizan?' He said: 'Then seek me at the Hawd, for indeed I will not me missed at these three locations