A man who reaches the imam after he has said a takbir: does he join him or wait until he says the next?

Al-Harith said: When a man arrives at the funeral prayer after the imam has already said some takbirs, he should not say the takbir immediately, but should wait for the imam's takbir (and then enter the prayer).

Al-Hasan said: If someone comes to the funeral prayer while the people are offering it, he should join them by saying a takbir (and not wait for the imam's takbir).