It's likely you're thinking of "point of the spear".
"Point of the spear" is a metaphor that refers to the leading edge or forefront of any activity or effort. It implies being at the most crucial, risky, or challenging position, often involved in direct action or confrontation.
Here are some examples of how it's used:
* "The new marketing campaign is at the point of the spear in our efforts to increase brand awareness."
* "Our soldiers at the point of the spear faced fierce resistance in the battle."
* "The research team is at the point of the spear in developing new cancer treatments."
The idiom is rooted in the imagery of a spear, where the tip is the sharpest and most dangerous part, indicating where the most direct force is applied.