حِصْنُ الْمُسْلِمِ
Hisn al-Muslim 161
Fortress of the Muslim (Hisn al-Muslim)
When the deceased is a child, during the funeral prayer
اللهُـمِّ اجْعَلْـهُ لَنا فَرَطـاً، وَسَلَـفاً وَأَجْـراً
Allāhumma’j`alhu lanā faraṭan, wa salafan, wa ajra. O Allah, make him for us a precursor, a forerunner and a cause of reward. Reference: Al-Hasan (Al-Basri) used to recite Surat Al-Fatihah for a child's funeral and then say this. Al-Bukhari, Kitabul-Jana'iz, p. 65.
Hisn al-Muslim, 161