Sunan Abi Dawud 769
سنن أبي داود#769Sahihحَدَّثَنَا الْقَعْنَبِيُّ، عَنْ مَالِكٍ، قَالَ لاَ بَأْسَ بِالدُّعَاءِ فِي الصَّلاَةِ فِي أَوَّلِهِ وَأَوْسَطِهِ وَفِي آخِرِهِ فِي الْفَرِيضَةِ وَغَيْرِهَا .
Malik said:There is no harm in uttering supplication in prayer, in its beginning, in its middle, and in the end, in obligatory prayer or other
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Al-AlbaniSahih Maqtu
Muhammad Muhyi Al-Din Abdul HamidSahih Maqtu
Zubair Ali ZaiIsnaad Sahih
In-book reference: 2:379