The Sunnah with regard to reciting Soorat al-Sajdah and al-Insaan in full in Fajr on Fridays

We cannot say that what they are doing is bid’ah, but we can
say that what they are doing is playing with the Sunnah. If they were really
sincere about following the Prophet (peace and blessings of Allaah be
upon him) then let them do what he did. Hence Ibn al-Qayyim (may Allaah have
mercy on him) described people like this as ignorant imams. We say: If you
are able to recite Soorat al-Sajdah in the first rak’ah and Soorat al-Insaan
in the second, then do that. If you are not able to do that then recite
another soorah so that you will not be dividing the Sunnah and toying with
it. The Sunnah is known: the Prophet (peace and blessings of Allaah be
upon him) used to recite Soorat al-Sajdah in the first rak’ah of Fajr on
Friday and Soorat al-Insaan in the second rak’ah. So you should either do
what the Prophet (peace and blessings of Allaah be upon him) did, or
recite another soorah, because dividing or separating what the Prophet
(peace and blessings of Allaah be upon him) did is going against the Sunnah
and is undoubtedly toying with the Sunnah. Follow the guidance of your
Prophet Muhammad (peace and blessings of Allaah be upon him) and be
courageous, because if you recite Soorat al-Sajdah in the first rak’ah and
Soorat al-Insaan in the second, some imams will say, “Why did you recite for
so long? The Prophet (peace and blessings of Allaah be upon him) got
angry with Mu’aadh (may Allaah be pleased with him) and rebuked him for
that.” 

But we say: Everything that the Prophet (peace and
blessings of Allaah be upon him) did was reasonable and not heavy, even if
he recited Soorat al-Sajdah and al-Isnaan. Hence Anas ibn Maalik (may Allaah
be pleased with him) said: “I never prayed behind any imam whose prayer was
lighter and more complete than the Messenger of Allaah (peace and
blessings of Allaah be upon him).”