Romans 3:12 They are all gone out of the way, they are together become unprofitable; there is none that doeth good, no, not one.
Romans 3:13 Their throat is an open sepulchre; with their tongues they have used deceit; the poison of asps is under their lips:
The reference they lie in wait for blood pertains to their mouths
Prov 12:6 The words of the wicked are to lie in wait for blood: but the mouth of the upright shall deliver them.
Similar to lying in wait here with Jesus
Luke 11:54 Laying wait for him, and seeking to catch something out of his mouth, that they might accuse him.
And with Paul
Acts 20:19 Serving the Lord with all humility of mind, and with many tears, and temptations, which befell me by the lying in wait of the Jews:
The mouth of the upright, being the LORD shall delivere them as shown here
2 Ti 4:17 Notwithstanding the Lord stood with me, and strengthened me; that by me the preaching might be fully known, and that all the Gentiles might hear: and I was delivered out of the mouth of the lion.
2 Ti 4:18 And the Lord shall deliver me from every evil work, and will preserve me unto his heavenly kingdom: to whom be glory for ever and ever. Amen.
The mouth of wisdom, or as Jesus said,
Mat 10:20 For it is not ye that speak, but the Spirit of your Father which speaketh in you.
Rolling it around that way