A.T. Robertson Commentary Hebrews 3:7

"Wherefore, even as the Holy Spirit saith, To-day if ye shall hear his voice," — Hebrews 3:7 (ASV)

Wherefore (διο). Probably this inferential conjunction (δια, ο, because of which) goes with μη σκληρυνητε (harden not) in verse 8 rather than with βλεπετε (take heed) in verse 12 unless the long quotation be considered a parenthesis. The long quotation in verses 7-11 is from Ps 95:7-11. After the quotation the author has "three movements" (Moffatt) in his discussion of the passage as applied to the Jewish Christians (3:12-19; 4:1-10; 4:11-13). The peril of apostasy as shown by the example of the Israelites is presented with vividness and power.

As the Holy Ghost saith (καθως λεγε το πνευμα το αγιον). Just this phrase nowhere else in the N.T., except Act 21:11 (Agabus), though practically the same idea in 9:8; 10:15. In 1 Timothy 4:1 the adjective "Holy" is wanting as in Re 2; 3. But the writer quotes this Psalm as the Word of God and in 4:7 attributes it to David.

If ye shall hear (εαν ακουσητε). Condition of third class with εαν and first aorist active subjunctive of ακουω.