Al-Husayn ibn Sa’id narrated from Safwan ibn Yahya from ‘Is ibn al-Qasim. He said:
I asked Abu Abdillah عليه السلام, peace be upon him, about a man who catches one takbir from the prayer over the deceased (Salat Al Mayyit). Imam عليه السلام said: “He completes what remains (of the Salat Al Mayyit).”
Ali Akbar al-Ghaffari
Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 3, p. 220