a matter of (something)

an amount that can be measured.

The guards will react to an alarm call within a matter of minutes.

We were off our course by a matter of ten to twenty miles to the west.

• a trump card
• at sea
• at service
• at someone's beck and call
• at someone's elbow
• at someone's heels
• at someone's knee
• at someone's service
• at stake
• attend to
• attend to someone
• attend to something
• at the back of beyond
• at the back of mind
• at the back of your mind
• at the best of times
• at the bottom of the heap
• at the bottom of the ladder
• at the bottom of the pile
• at the chalkface
• at the coalface
• at the crack of dawn
• at the cutting edge
• at the double
• at the drop of a hat