My father said, "The Prophet ﷺ used to prolong the first rakʿa of the Zuhr prayer and shorten the second one and used to do the same in the Fajr prayer."
أَنَّ النَّبِيَّ ﷺ كَانَ يُطَوِّلُ فِي الرَّكْعَةِ الأُولَى مِنْ صَلاَةِ الظُّهْرِ وَيُقَصِّرُ فِي الثَّانِيَةِ وَيَفْعَلُ ذَلِكَ فِي صَلاَةِ الصُّبْحِ
“The Messenger of Allah ﷺ used to lead us in prayer, and he would lengthen the first Rak’ah of the Zuhr and shorten the second Rak’ah, and he would do likewise in the Subh.”
كَانَ رَسُولُ اللَّهِ ﷺ يُصَلِّي بِنَا فَيُطِيلُ فِي الرَّكْعَةِ الأُولَى مِنَ الظُّهْرِ وَيُقْصِرُ فِي الثَّانِيَةِ وَكَذَلِكَ فِي الصُّبْحِ
[Machine] The Messenger of Allah ﷺ used to recite longer in the first two units of the Dhuhr prayer and shorten in the second two units, and he would do the same in the Fajr prayer.
كَانَ رَسُولُ اللهِ ﷺ يَقْرَأُ فِي الرَّكْعَتَيْنِ الْأُولَيَيْنِ مِنْ صَلَاةِ الظُّهْرِ يُطِيلُ فِي الْأُولَى وَيُقَصِّرُ فِي الثَّانِيَةِ وَيَفْعَلُ ذَلِكَ فِي صَلَاةِ الصُّبْحِ