§ 1333 Courts which may grant writ - Grant without delay.

Here's a plain English summary of this rule:

If someone is being held in custody and wants to challenge whether that detention is legal, they can ask for a writ of habeas corpus. This rule explains who has the power to grant that writ. Any court of record can grant it while court is in session, and a judge from that court can grant it whether court is currently in session or not.

The rule also makes clear that once someone properly asks for this writ, the court or judge must grant it right away. There's no room for delay or putting it off. This matters because habeas corpus deals with a person's freedom, so the law wants these requests handled quickly rather than sitting on a judge's desk.

In short, this rule gives judges broad power to issue this writ at almost any time, and it requires them to act fast once someone asks for one.