As-Saduq believes, that women should place their hands on their chest in prayer

Muhammad ibn Ali As-Saduq writes:

لَـيْـسَ عَـلَـى الْـمَـرْأَةِ أَذَانٌ وَلَا إِقَـامَـةٌ وَلَا جُـمُـعَـةٌ وَلَا جَـمَـاعَـةٌ وَإِذَا قَـامَـتِ الْـمَـرْأَةُ فِـي صَـلَاتِـهَـا جَـمَـعَـتْ بَـيْـنَ قَـدَمَـيْـهَـا وَلَـمْ تُـفَـرِّجْ بَـيْـنَـهُـمَـا وَوَضَـعَـتْ يَـدَيْـهَـا عَـلَـى صَـدْرِهَـا لِـمَـكَـانِ ثَـدْيَـيْـهَـا فَـإِذَا رَكَـعَـتْ وَضَـعَـتْ يَـدَيْـهَـا فَـوْقَ رُكْـبَـتَـيْـهَـا عَـلَـى فَـخْـذَيْـهَـا لَـئِـلَّا تَـطَـأْطَـأَ كَـثِـيـرًا فَـتَـرْتَـفِـعَ عَـجِـيـزَتُـهَـا وَإِذَا أَرَادَتِ الـسُّـجُـودَ جَـلَـسَـتْ ثُـمَّ سَـجَـدَتْ لَاطِـئَـةً بِـالْأَرْضِ وَتَـضَـعُ ذِـرَاعَـيْـهَـا فِـي الْأَرْضِ فَإِذَا أَرَادَتِ الـنُّهُـوضَ إِلَـى الْـقِـيَـامِ رَفَـعَـتْ رَأْسَـهَـا مِـنَ الـسُّـجُـودِ وَجَـلَـسَـتْ عَـلَـى أَلْـيَـتَـيْـهَـا لَـيْـسَ كَـمَـا يُـقْـعِـي الـرَّجُـلُ ثُـمَّ نَـهَـضَـتْ إِلَـى الْـقِـيَـامِ مِـنْ غَـيْـرِ أَنْ تَـرْفَـعَ عَـجِـيـزَتَـهَـا تَـنْـسَـلُّ انْـسِـلَالًا وَإِذَا قَـعَـدَتْ لِـلـتَّـشَـهُّـدِ رَفَـعَـتْ رِجْـلَـيْـهَـا وَضَـمَّـتْ فَـخْـذَيْـهَـا وَالْـحُـرَّةُ لَا تُـصَـلِّـي إِلَّا بِـقِـنَـاعٍ وَالْأَمَةُ تُـصَـلِّـي بِـغَـيْـرِ قِـنَـاعٍ

,,It is not obligatory upon the woman to call for the prayer (adhan), nor for the congregational call (iqamah), nor the Friday prayer, nor the congregational prayer and when the woman stands in her prayer, she places her two feet close together, leaving no space between them and she puts her two hands on her chest. In the place of her two breasts. When she bows down, she puts her hands above her knees on her two thighs so that she does not bend too much, whereupon her buttocks is lifted and when she wants to prostrate, she sits down. She then prostrates close to the ground and puts both her arms on the ground.When she wants to stand up, she raises her head from prostration and sits on her two buttocks. Not like the man sits. On this, she stands up without lifting her buttocks. She steals herself away from this and when she sits down for confession (Tashahhud) she lifts her feet and presses her thighs together and the free woman does not pray except with a veil and the slave woman prays without a veil.” [Man La Yahduruh-ul-Faqih, Volume 1, page 259]