TABARANI 16134:
from ʿAbd al-Malik b. Qatādah b. Milḥān al-Qaysī from his father —
[Machine] The Messenger of Allah ﷺ used to command us to fast the white days, which are the thirteenth, fourteenth, and fifteenth of each lunar month, and he said, "It is the perpetual fast." "And their wording is one."
الطبراني ١٦١٣٤:
عن عبد الملك بن قتاده بن ملحان القيسي عن أبيه —
كَانَ رَسُولُ اللهِ ﷺ يَأْمُرُنَا أَنْ نَصُومَ أَيَّامَ الْبِيضِ ثَلَاثَ عَشْرَةَ وَأَرْبَعَ عَشْرَةَ وَخَمْسَ عَشْرَةَ وَقَالَ «وَهُوَ صَوْمُ الدَّهْرِ» «وَلَفْظُهُمْ وَاحِدٌ»
hadithunlocked.com