ʿUyūn akhbār al-Riḍā - Volume 1 > On al-Ridha’s Words About the Man From Syria and His Questions From the Commander of the Faithful (s) in the Kufa Mosque
Hadith #2

2 - حَدَّثَنا مُحَمَّدِ بْنِ مُوسَى بْنِ المُتَوَكِّل رَضِىَ اللهُ عَنْهُ قالَ: حَدَّثَنا عَبْدِ اللَّه بْنِ جَعْفَر الحِمْيَريُّ عَنْ إِبْراهيمِ بْنِ هاشِم، عَن أَحْمَدِ بْنِ عامِر الطَّائيّ قالَ: سَمِعتُ أَبَا الحَسَن عَلِىِّ بْنِ مُوسَى الرِّضا عَلَيْهِ السَّلامُ يَقُولُ يَوْمُ الأَرْبِعَاءِ يَوْمُ نَحْسٍ مُسْتَمِرٍّ مَنِ احْتَجَمَ فِيهِ خِيفَ أَنْ تَخْضَرَّ مَحَاجِمُهُ وَمَنِ انْتَارَ فِيهِ خِيفَ عَلَيْهِ الْبَرَصُ.

24-2 Muhammad ibn Musa ibn al-Mutawakkil -may God be pleased with him- narrated that Abdullah ibn Ja’far al-Himyari quoted on the authority of Ibrahim ibn Hashem, on the authority of Ahmad ibn Aamir Al-Ta’ee, “I heard Abul Hassan Ali ibn Musa Al-Ridha (s) say, ‘Wednesdays are bad days with a bad omen. Whoever performs a phlebotomy (blood-letting) on that day should fear that it leaves a bruise behind. And whoever removes his hair, wool, or bristles on that day should fear to get leprosy.’”