HoldPattern

HoldPattern[expr] is equivalent to expr for pattern matching, but maintains expr in an unevaluated form.

Examples

Match unevaluated expressions:

Cases[{1 + 1, 2 + 2, Hold[3 + 3]}, HoldPattern[_ + _]]
(* {1 + 1, 2 + 2} - matches before evaluation *)

Use in rules:

{1 + 1, 2 + 3} /. HoldPattern[a_ + b_] :> {a, b}

Please visit the official Wolfram Language Reference for more details.