The phrase "to grab a pair" means to quickly take or get hold of something, usually two things.
Sentences with «to grab a pair»
For instance, I'm thinking of grabbing a pair of neon heels — they would be wearable later for some fun event and will help me bring the trend into my closet. (modlychic.com)
My sister grabbed a pair for me off the clearance rack! (themomedit.com)
So grab a pair of thick and cozy socks and whip up some of this scrumptious soup... and then enjoy the yummy compliments passed around the table to you. (jenniferskitchen.com)