Imam and congregation offering du‘aa’ together following Jumu‘ah prayer

Question

Praise be to Allah.

What the believers should do is follow
the example of the Prophet (blessings and peace of Allah be upon him) with
regard to what he did and did not do. He should do what the Messenger
(blessings and peace of Allah be upon him) did and refrain from that from
which the Messenger (blessings and peace of Allah be upon him) refrained.
Allah, may He be exalted, said (interpretation of the meaning):

“Indeed in the Messenger of Allah
(Muhammad SAW) you have a good example to follow for him who hopes in (the
Meeting with) Allah and the Last Day …”

[al-Ahzaab 33:21].

Du‘aa’ by the imam after an obligatory
prayer – Jumu‘ah or otherwise – with the congregation saying Ameen is
something that was not done by the Messenger (blessings and peace of Allah
be upon him) or by any of his Companions (may Allah be pleased with them).
If it was good, they would have done it before us.

Based on that, this action comes under the
heading of reprehensible innovation. The Prophet (blessings and peace of
Allah be upon him) said: “Whoever among you lives after I am gone will see
great disputes; you must adhere to my Sunnah and the way of the Rightly
Guided Caliphs. Hold on to it and cling fast to it. And beware of
newly-invented matters, for every newly-invented matter is an innovation and
every innovation is a going astray.”

Narrated by Abu Dawood, 4607; classed as
saheeh by al-Albaani in Saheeh Abi Dawood.

And the Prophet (blessings and peace of
Allah be upon him) said: “Whoever introduces something into this matter of
ours that is not part of it will have it rejected.”

Narrated by al-Bukhaari, 2697; Muslim,
1718.

Ash-Shaatibi (may Allah have mercy on him)
mentioned congregational du‘aa’ after the obligatory prayer in his book
al-I‘tisaam (1/349-355), and explained that this is an innovation,
because that was not done by the Messenger (blessings and peace of Allah be
upon him) or by any of his Companions (may Allah be pleased with them) or
any of the imams (leading scholars) after them.

What you must do is refrain from this
innovation and strive to recite the adhkaar and du‘aa’s that the Prophet
(blessings and peace of Allah be upon him) used to say after the prayer. And
whoever wants to offer du‘aa’ may do so quietly.

See also the answer to questions no.
10491 and
21976

And Allah knows best.