مُحَمَّدُ بْنُ يَحْيَى عَنْ أَحْمَدَ بْنِ مُحَمَّدٍ عَنِ ابْنِ فَضَّالٍ عَنِ الْحَسَنِ بْنِ الْجَهْمِ قَالَ قَالَ سَمِعْتُ أَبَا الْحَسَنِ الرِّضَا ( عليه السلام ) يَقُولُ قَالَ أَبُو جَعْفَرٍ ( عليه السلام ) إِنَّ النُّطْفَةَ تَكُونُ فِي الرَّحِمِ أَرْبَعِينَ يَوْماً ثُمَّ تَصِيرُ عَلَقَةً أَرْبَعِينَ يَوْماً ثُمَّ تَصِيرُ مُضْغَةً أَرْبَعِينَ يَوْماً فَإِذَا كَمَلَ أَرْبَعَةُ أَشْهُرٍ بَعَثَ اللَّهُ مَلَكَيْنِ خَلَّاقَيْنِ فَيَقُولَانِ يَا رَبِّ مَا تَخْلُقُ ذَكَراً أَوْ أُنْثَى فَيُؤْمَرَانِ فَيَقُولَانِ يَا رَبِّ شَقِيّاً أَوْ سَعِيداً فَيُؤْمَرَانِ فَيَقُولَانِ يَا رَبِّ مَا أَجَلُهُ وَ مَا رِزْقُهُ وَ كُلُّ شَيْ‏ءٍ مِنْ حَالِهِ وَ عَدَّدَ مِنْ ذَلِكَ أَشْيَاءَ وَ يَكْتُبَانِ الْمِيثَاقَ بَيْنَ عَيْنَيْهِ فَإِذَا أَكْمَلَ اللَّهُ لَهُ الْأَجَلَ بَعَثَ اللَّهُ مَلَكاً فَزَجَرَهُ زَجْرَةً فَيَخْرُجُ وَ قَدْ نَسِيَ الْمِيثَاقَفَقَالَ الْحَسَنُ بْنُ الْجَهْمِ فَقُلْتُ لَهُ أَ فَيَجُوزُ أَنْ يَدْعُوَ اللَّهَ فَيُحَوِّلَ الْأُنْثَى ذَكَراً وَ الذَّكَرَ أُنْثَى فَقَالَ إِنَّ اللَّهَ يَفْعَلُ مَا يَشَاءُ .
3. Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad from ibn Faddal from al-Hassan ibn al-Jahm who has said the following: “Abu Ja‘far , has said, ‘Sperm in the womb after forty days becomes a clot and after forty days thereafter it becomes an embryo. When four months are complete Allah sends two creating angels and they ask, “O Lord, what do You want to create? Do You want to create a male or a female.” They then receive the command. Thereafter they ask, “O Lord, do You want him to be virtuous or a wicked one?” They then receive the command. They ask, “O Lord, how much is the length of his life, how much is his sustenance, everything of his condition and the number of such things?” They write the covenant between his eyes. When the time of pregnancy is complete, Allah sends an angel who scolds him harshly. He comes out but has already forgotten the covenant.’ Al-Hassan ibn al-Jahm has said, that I then asked him (the Imam), ‘Will Allah because of prayer change female to a male and a male into a female?’ He (the Imam) said, ‘Allah can do whatever He wants.’” 