al-Salamu `Aleykum,

according to al-Kafi, Ja`far al-Sadiq (rah) used to add words to the Qur’an.

– al-Kafi vol 8 pg 290, Authenticated by Majlisi 26/316:
عَلِيُّ بْنُ إِبْرَاهِيمَ عَنْ أَبِيهِ عَنْ عَلِيِّ بْنِ أَسْبَاطٍ عَنْ عَلِيِّ بْنِ أَبِي حَمْزَةَ عَنْ أَبِي بَصِيرٍ عَنْ أَبِي عَبْدِ اللَّهِ ( عليه السلام ) وَ اتَّبَعُوا ما تَتْلُوا الشَّياطِينُ بِوَلَايَةِ الشَّيَاطِينِ عَلى مُلْكِ سُلَيْمانَ وَ يَقْرَأُ أَيْضاً سَلْ بَنِي إِسْرائِيلَ كَمْ آتَيْناهُمْ مِنْ آيَةٍ بَيِّنَةٍ فَمِنْهُمْ مَنْ آمَنَ وَ مِنْهُمْ مَنْ جَحَدَ وَ مِنْهُمْ مَنْ أَقَرَّ وَ مِنْهُمْ مَنْ بَدَّلَ وَ مَنْ يُبَدِّلْ نِعْمَةَ اللَّهِ مِنْ بَعْدِ ما جاءَتْهُ فَإِنَّ اللَّهَ شَدِيدُ الْعِقابِ .

[`Ali bin Ibrahim from his father from `Ali bin Asbat from `Ali bin abi Hamzah from abu Baseer from abu `Abdillah (as):
{And they followed [instead] what the devils had recited with the authority of the devils during the reign of Solomon.}
And he also recited:
{Ask the Children of Israel how many a sign of evidence We have given them. So from them is he who believed, and from them is he who rejected, and from them is he who affirmed, and from them is he who changed, And whoever exchanges the favor of Allah [for disbelief] after it has come to him – then indeed, Allah is severe in penalty.}]

Correct verses are as follows:
{And they followed [instead] what the devils had recited during the reign of Solomon.} (Qur’an 2:102)

and:
{Ask the Children of Israel how many a sign of evidence We have given them. So from them is he who believed, and from them is he who believed, and from them is he who affirmed, and from them is he who changed, And whoever exchanges the favor of Allah [for disbelief] after it has come to him – then indeed, Allah is severe in penalty.} (Qur’an 2:211)

– al-Kafi vol 8 pg 184, authenticated by Majlisi 26/75:
عَنْهُ عَنْ أَبِيهِ عَنْ عَلِيِّ بْنِ أَسْبَاطٍ عَنْ عَلِيِّ بْنِ أَبِي حَمْزَةَ عَنْ أَبِي بَصِيرٍ عَنْ أَبِي عَبْدِ اللَّهِ ( عليه السلام ) وَ لَوْ أَنَّا كَتَبْنا عَلَيْهِمْ أَنِ اقْتُلُوا أَنْفُسَكُمْ وَ سَلِّمُوا لِلْإِمَامِ تَسْلِيماً أَوِ اخْرُجُوا مِنْ دِيارِكُمْ رِضًا لَهُ ما فَعَلُوهُ إِلَّا قَلِيلٌ مِنْهُمْ وَ لَوْ أَنَّ أَهْلَ الْخِلَافِ فَعَلُوا ما يُوعَظُونَ بِهِ لَكانَ خَيْراً لَهُمْ وَ أَشَدَّ تَثْبِيتاً وَ فِي هَذِهِ الْآيَةِ ثُمَّ لا يَجِدُوا فِي أَنْفُسِهِمْ حَرَجاً مِمَّا قَضَيْتَ مِنْ أَمْرِ الْوَالِي وَ يُسَلِّمُوا لِلَّهِ الطَّاعَةَ تَسْلِيماً .
[`Ali bin Ibrahim from his father from `Ali bin Asbat from `Ali bin abi Hamzah from abu Baseer from abu `Abdillah (as):
{And if We had decreed upon them, “Kill yourselves and submit to the Imam in (full, willing) submission or Leave your homes,” they would not have done it, except for a few of them. And if the opponents did what they were instructed to do, it would have been better for them and a firmer position [for them in faith].} and in this verse: {and then find within themselves no discomfort from what you have judged in the matter of the leadership, and submit to Allah their obedience in [full, willing] submission.}]

Correct verses are as follows:
{And if We had decreed upon them, “Kill yourselves” or “Leave your homes,” they would not have done it, except for a few of them. But if they had done what they were instructed, it would have been better for them and a firmer position [for them in faith].}
(Qur’an 4:66)

And:
{But no, by your Lord, they will not [truly] believe until they make you, [O Muhammad], judge concerning that over which they dispute among themselves and then find within themselves no discomfort from what you have judged and submit in [full, willing] submission.}
(Qur’an 4:65)

– al-Kafi vol 8 pg 205, authenticated by Majlisi 26/118:
عَلِيُّ بْنُ إِبْرَاهِيمَ عَنْ أَبِيهِ عَنِ ابْنِ أَبِي عُمَيْرٍ عَنْ حَمَّادِ بْنِ عُثْمَانَ قَالَ تَلَوْتُ عِنْدَ أَبِي عَبْدِ اللَّهِ ( عليه السلام ) ذَوا عَدْلٍ مِنْكُمْ فَقَالَ ذُو عَدْلٍ مِنْكُمْ هَذَا مِمَّا أَخْطَأَتْ فِيهِ الْكُتَّابُ .

[`Ali bin Ibrahim from his father from ibn abi `Umayr from Hammad bin `Uthman that he said: I recited to abu `Abdullah (as) {Two just men from among you} he said it is {A just man among you}: “This is from the mistakes of the writers.”]

Correct verse is as follows:
{O you who have believed, do not kill game while you are in the state of ihram. And whoever of you kills it intentionally – the penalty is an equivalent from sacrificial animals to what he killed, as judged by two just men among you as an offering [to Allah] delivered to the Ka’bah, or an expiation: the feeding of needy people or the equivalent of that in fasting, that he may taste the consequence of his deed. Allah has pardoned what is past; but whoever returns [to violation], then Allah will take retribution from him. And Allah is Exalted in Might and Owner of Retribution.} (Qur’an 5:95)

What do all these have in common? `Ali bin Ibrahim and his trusty father Ibrahim bin Hashim al-Qummi ; )

As for those who will say anything regarding ibn abi Hamzah, al-Tusi said he was reliable in al-`Iddah.