Here are a few narrations from our books that I was able to find that discuss the washing of the hearts, the black spot being removed, etc.
علي بن إبراهيم ، عن أبيه ، عن ابن أسباط ومحمد بن أحمد ، عن موسى بن القاسم البجلي ، عن علي بن أسباط قال قلت لأبي الحسن الرضا عليهالسلام جعلت فداك ما ترى آخذ برا أو بحرا فإن طريقنا مخوف شديد الخطر فقال اخرج برا ولا عليك أن تأتي مسجد رسول الله صلىاللهعليهوآله وتصلي ركعتين في غير وقت فريضة ثم لتستخير الله مائة مرة ومرة ثم تنظر فإن عزم الله لك على البحر فقل الذي قال الله عز وجل «وَقالَ ارْكَبُوا فِيها بِسْمِ اللهِ مَجْراها وَمُرْساها إِنَّ رَبِّي لَغَفُورٌ رَحِيمٌ» فإن اضطرب بك البحر فاتك على جانبك الأيمن وقل بسم الله اسكن بسكينة الله وقر بوقار الله واهدأ بإذن الله ولا حول ولا قوة إلا بالله قلنا أصلحك الله ما السكينة ريح تخرج من الجنة لها صورة كصورة الإنسان ـ ورائحة طيبة وهي التي نزلت على إبراهيم فأقبلت تدور حول أركان البيت وهو يضع الأساطين قيل له هي من التي قال الله عز وجل : «فِيهِ سَكِينَةٌ مِنْ رَبِّكُمْ وَبَقِيَّةٌ مِمَّا تَرَكَ آلُ مُوسى وَآلُ هارُونَ» قال تلك السكينة في التابوت وكانت فيه طشت تغسل فيها قلوب الأنبياء وكان التابوت يدور في بني إسرائيل مع الأنبياء ثم أقبل علينا فقال ما تابوتكم قلنا السلاح قال صدقتم هو تابوتكم وإن خرجت برا فقل الذي قال الله عز وجل «سُبْحانَ الَّذِي سَخَّرَ لَنا هذا وَما كُنَّا لَهُ مُقْرِنِينَ. وَإِنَّا إِلى رَبِّنا لَمُنْقَلِبُونَ» فإنه ليس من عبد يقولها عند ركوبه فيقع من بعير أو دابة فيصيبه شيء بإذن الله ثم قال فإذا خرجت من منزلك فقل بسم الله آمنت بالله توكلت على الله لا حول ولا قوة إلا بالله ـ فإن الملائكة تضرب وجوه الشياطين ويقولون قد سمى الله وآمن بالله وتوكل على الله وقال لا حول ولا قوة إلا بالله
5. Ali b. Ibrahim from his father (Ibrahim b. Hashim) from Ibn Asbat AND Muhammad b. Ahmad from Musa b. al-Qasim al-Bajali from Ali b. Asbat who said:
I said to Abi al-Hasan al-Ridha عليه السلام: may I be made your ransom - should I go by way of land or sea - for our journey is fearful and very dangerous?
So he said: go out by way of land - and there is nothing upon you (no harm upon you) that you go to the Masjid of the messenger of Allah and pray a two unit prayer in other than the time of the obligatory prayer, then you supplicate to Allah for the best option a hundred and one times, then you observe - so if Allah decides the sea for you (by casting this decision into your heart) then say what Allah the Mighty and Majestic said: “And say: embark upon it - in the name of Allah be its sailing and anchoring - verily my Lord is most forgiving the merciful” (11:41), so if the sea is tumultuous then take support (lean) on your right side and say: “in the name of Allah - be tranquil by the tranquility of Allah and be calm by the calmness of Allah and be aright (quiet down) by the will of Allah - and there is no strength nor power save by Allah”.
We said: may Allah grant you prosperity - what is the Sakina?
He said: a wind that comes from paradise - it has a face like the face of a man and good fragrance, and it is the one which descended upon Ibrahim so it began revolving around the pillars of the House (Ka’ba) while he was setting up the beams .
It was said to him: is it the one about which Allah the Mighty and Majestic said: “In it - a Sakina - from your lord and remnants [relics] from that which was left by the family of Musa and the family of Harun” (2:248)?
He said: that is the Sakina of the ark (of the covenant), and in it (i.e. the ark) was a basin in which was washed the hearts of the prophets, and the ark used to move around in Bani Israil only among the prophets.
Then he turned to us and said: what is your ark?
We said: the weapons (of the messenger of Allah)
He said: you have spoken the truth - it is your ark.
And if you go by way of land [on the back of an animal] then say that which was said by Allah the Mighty and Majestic: “Praised be the one who has made this submissive to us and we could not have otherwise subdued it and to our lord are we to return” (43:13) for there is not a slave who says it whence he climbs on (and begins a journey) and then goes on to fall off his camel or animal and gets hurt - by the will of Allah.
Then he said: and when you leave your house say: “In the name of Allah, I have believed in Allah, I have depended on Allah, there is no strength nor power save by Allah” for the angels beat the faces of the devils and they say: he (the man) has named Allah, and believed in Allah, and depended upon Allah, and said: there is no strength nor power save by Allah. (Muwathaq - Translated by Islamic Salvation)
Source:
al-Kulayni, al-Kafi, vol. 3, pg. 471-472, hadith # 5
ثُمَّ إِنَّ جَبْرَائِيلَ ع أَلْقَى رَسُولَ اللَّهِ ص عَلَى قَفَاهُ وَ رَفَعَ أَثْوَابَهُ فَقَالَ لَهُ النَّبِيُّ ص مَا تُرِيدُ تَصْنَعُ يَا أَخِي جَبْرَائِيلُ فَقَالَ جَبْرَائِيلُ لَا بَأْسَ عَلَيْكَ فَأَخْرَجَ جَنَاحَهُ «3» وَ شَقَّ بَطْنَ النَّبِيِّ ص وَ أَدْخَلَ جَنَاحَهُ فِي بَطْنِهِ وَ خَرَقَ قَلْبَهُ وَ شَقَّ المقلبة وَ أَظْهَرَ نُكْتَةً سَوْدَاءَ فَأَخَذَهَا جَبْرَائِيلُ ع فَغَسَلَهَا وَ مِيكَائِيلُ يَصُبُّ الْمَاءَ عَلَيْهِ فَنَادَى مُنَادٍ مِنَ السَّمَاءِ يَقُولُ يَا جَبْرَائِيلُ لَا تَقْشِرْ قَلْبَ مُحَمَّدٍ ص فَتُوجِعَهُ وَ لَكِنِ اغْسِلْهُ بِزَغَبِكَ وَ الزَّغَبُ هُوَ الرِّيشُ الَّذِي تَحْتَ الْجَنَاحِ فَأَخَذَ جَبْرَئِيلُ زَغَبَةً وَ غَسَلَ بِهَا قَلْبَ مُحَمَّدٍ ص ثُمَّ رَدَّ المقلبة إِلَى الْقَلْبِ وَ الْقَلْبَ إِلَى الصَّدْرِ
Then Jibra'eel met the Messenger of Allah, and he stoped himand lifted his (pbuh) shirt. The Prophet (pbuh) said to him (Jibra'eel), 'What are you intending to do, O my brother Jibra'eel?' Jibra'eel said: 'There is no problem upon you, and he took his win and split the chest of the Prophet, and he (Jibra'eel) entered his wing in his (pbuh) chest, and penetrating his (pbuh) heart, split it and turned it (?) and it revealed a black spot, so he (Jibra'eel) took it and washed it, and Mika'eel was pouring water on it, then a call from a caller in the heavens says: 'O Jibra'eel, do not peel the heart of Muhammad (pbuh), for it pains him,but wash it with your fluffy (feathers), the fluffy (feathers) is the feather which is under the wing. So Jibra'eel took the fluffy (feathers) and he washed with it the heart of Muhammad, then returned turn (?) to the heart and the earth to the chest
Source:
Ibn Shaadhaan al-Qummi, Fadaa'il (Qum: Radi Publications, 1405), pg. 34
al-Majlisi, Bihaar al-Anwar, vol. 15, ch. 4, hadith # 13, pg. 356
وَ مَعَهُ طَسْتٌ مِنْ ذَهَبٍ مَضْرُوبٍ مِنْ زُمُرُّدٍ وَ مُشْطٌ مِنْ ذَهَبٍ فَشَقَّ بَطْنَهُ شَقّاً ثُمَّ أَخْرَجَ قَلْبَهُ فَشَقَّهُ فَأَخْرَجَ مِنْهُ نُكْتَةً سَوْدَاءَ فَرَمَى بِهَا
And with him (Jibra’eel) was a tray of gold and it was studded with emeralds, and (he had) a comb of gold. So he (Jibra’eel) split his chest, then he took his heart and split it and took out from it a black spot, and he casted it out
Source:
al-Saduq, al-Amali, majlis #45, pg. 264, hadith # 2
al-Saduq, Kamal al-Deen, vol. 1, ch. 12, pg. 176, hadith # 33