Yahya related to me from Malik that he asked Ibn Shihab and Nafi,the mawla of Ibn Umar, whether a man who joined an imam who hadalready done a raka should say the tashahhud with the imam in thesecond and fourth rakas, even though these were odd for him? Theysaid, "He should say tashahhud with him."Malik said, "Thatis the position with us."
App reference: Book 3, Hadith 60
USC-MSA web (English) reference: Book 3, Hadith 60
Arabic reference: Book 3, Hadith 207