Sunan Ibn Majah
Sunan Ibn Majah 819
حَدَّثَنَا أَبُو بِشْرٍ، بَكْرُ بْنُ خَلَفٍ حَدَّثَنَا ابْنُ أَبِي عَدِيٍّ، عَنْ حَجَّاجٍ الصَّوَّافِ، عَنْ يَحْيَى بْنِ أَبِي كَثِيرٍ، عَنْ عَبْدِ اللَّهِ بْنِ أَبِي قَتَادَةَ، وَعَنْ أَبِي سَلَمَةَ، عَنْ أَبِي قَتَادَةَ، قَالَ كَانَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ يُصَلِّي بِنَا فَيُطِيلُ فِي الرَّكْعَةِ الأُولَى مِنَ الظُّهْرِ وَيُقْصِرُ فِي الثَّانِيَةِ وَكَذَلِكَ فِي الصُّبْحِ .
Unreviewed translation. All hadiths in this collection are available in five languages. Titles and introductions may remain in Arabic.
Abu Bishr Bakr ibn Khalaf narrated to us: Ibn Abi 'Adi narrated to us, from Hajjaj al-Sawwaf, from Yahya ibn Abi Kathir, from 'Abdullah ibn Abi Qatadah and from Abu Salamah, from Abu Qatadah, who said: The Messenger of Allah (peace and blessings be upon him) used to lead us in prayer, making the first rak'ah of Zuhr long and the second short; he did the same in Fajr.
Notes and open questions — unreviewed
The source gives two routes to Abu Qatadah and says the same lengthening/shortening pattern applied to Fajr.