It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that on the day of the Battle of Uhud, the Messenger of Allah (peace and blessings be upon him) said to Sayyiduna Sa'd bin Abi Waqqas (may Allah be pleased with him): "Aim at the chests of the enemy, may my father and mother be ransomed for you!" So Sayyiduna Sa'd (may Allah be pleased with him) would place his arrow in the middle of his bow and say: 'Allahumma sahmuka wa fi sabilika, Allahumma unsur rasulaka' (O Allah, this is Your arrow and it is in Your path; O Allah, help Your Messenger). The Messenger of Allah (peace and blessings be upon him) then supplicated: 'Allahumma istajib li-Sa'din idha da'aka' (O Allah, answer Sa'd when he calls upon You).
Imam al-Tabarani (may Allah have mercy on him) said: "No one narrated this hadith from Abu Sa'd (al-Baqqal) except Abd al-Rahman bin Maghra'."
Hadith Referenceالمعجم الأوسط / باب العين / 4069
Hadith Gradingمحدثین:فيه أبو سعد البقال وهو مدلس
Hadith Takhrij«قال الهيثمي: فيه أبو سعد البقال وهو مدلس ثقة وقد اعتضد حديثه بالحديثين اللذين تقدما في باب إجابة دعائه «مجمع الزوائد ومنبع الفوائد، ج 9، ص 155»»