Prayer (Kitab Al-Salat)
2/128. Chapter:
The Supplication With Which The Prayer Should Be Started
Sunan Abi Dawud
حَدَّثَنَا 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.
Reference : Sunan Abi Dawud 769In-book reference : Book 2, Hadith 379English translation : Book 2, Hadith 768