Origion: Bibles usually had a black leather or paper cover. Since books were expensive a leather cover offered long term use and durability. Printing on the cover was usually in gold lettering.
More Archaic Definition: Bible black originally meant to quote Holy Scripture in such a way as to legitimize cruelty or other evils. The intent is always destructive, with the prideful desire to maintain the appearance of piety and propriety.
Usually, the Scripture has to be taken out of context to meet its dark goal so it will be parsed as a lawyer would to make the true point.
Example 1: Yes, well of course I hate you, "And I will hate you with a perfect hatred".
Ignoring John, "Whoever hates his brother does not remain in the light". Or Jesus, "Whoever hates his brother in his heart commits murder". Or Moses, "You will not hate your brother in your heart".
Example 2: "I've had enough of you and your Bible Black"
Pajama casual is a term used when working from home and preparing for a video conference. All business above the waist and your pajama pants down below.
We have a Zoom meeting in a few minutes and I’ll probably go pajama casual.