This supplication is made when the deceased is a baby/child (i.e. one not having reached the age of puberty).
(152)
After seeking forgiveness for the deceased, one can say:
اللهُـمِّ اجْعَلْـهُ فَرَطـاً وَذُخْـراً لِوالِـدَيه، وَشَفـيعاً مُجـاباً، اللهُـمِّ ثَـقِّلْ بِهِ مَوازيـنَهُما، وَأَعْـظِمْ بِهِ أُجـورَهُـما، وَأَلْـحِقْـهُ بِصالِـحِ الـمؤْمِنـين، وَاجْعَلْـهُ في كَفـالَةِ إِبْـراهـيم، وَقِهِ بِرَحْمَـتِكَ عَذابَ الْجَـحيم .
Allahummaj-AAalhu faratan, wathukhran liwalidayh, washafeeAAan mujaban. Allahumma thaqqil bihi mawazeenahuma wa-aAAthim bihi ojoorahuma, wa-alhiqhu bisalihil-mu/mineen, wajAAalhu fee kafalati Ibraheem, waqihi birahmatika AAathabal-jaheem.
‘O Allah, make him a preceding reward and a stored treasure for his parents, and an answered intercessor. O Allah, through him, make heavy their scales and magnify their reward. Unite him with the righteous believers, place him under the care of Ibraheem, and protect him by Your mercy from the torment of Hell.’
(153)
Al-Hasan used to recite the opening chapter of the Quran (i.e. AL-Fatihah) over the child and then supplicates:
اللهُـمِّ اجْعَلْـهُ لَنا فَرَطـاً، وَسَلَـفاً وَأَجْـراً.
Allahummaj-AAalhu lana farata, wasalafan wa-ajra.
‘O Allah, make him a preceding reward, a prepayment and a recompense for us.’