Charles Ellicott Commentary Romans 3:13

"Their throat is an open sepulchre; With their tongues they have used deceit: The poison of asps is under their lips:" — Romans 3:13 (ASV)

Their throat is an open sepulchre—that is, their speech is at once corrupt and corrupting. It is compared to a “yawning grave”—not merely to a pit into which a person may fall, but to a sort of pestiferous chasm, yawning and ravening, as it were, after its prey.

They have used deceit.—Strictly, they were deceiving; a continued action brought up to the present time.

Under their lips.—As the poison-bag of the serpent is directly under the kind of tooth by which its venom is discharged.