Bilal reported that he said: Messenger of Allah, do not say Amin before me.
Explanation & Benefits
Shaykh Umar Farooq Saeedi
937. Commentary:
That is, the prayer had already started, and he arrived late, so he said: Give me a chance so that I may also join the prayer and say Ameen with you. Its chain of narration is mursal, as there is a discussion regarding Abu Uthman’s meeting with Bilal radi Allahu anhu. However, Imam Daraqutni rahimahullah and others consider it to be connected (mawsul). [عون المعبود]
In any case, if it is said to the imam to lengthen the recitation a little and he accepts it, then there is no harm in it. It is mentioned in Sahih al-Bukhari: «باب اذا قيل للمصلي تقدم اوانتظر فانتظر فلا باس» [صحيح بخاري كتاب العمل فى الصلواة باب 14]
Source: Sunan Abu Dawood – Commentary by Shaykh Umar Farooq Saeedi, Page: 937