7-11. Exhortation from Ps 95:7-11, not through unbelief to lose participation in the spiritual house. Seeing that we are the house of God if we hold fast our confidence . . . (Heb 3:6). Jesus is "faithful," be not ye unfaithful (Heb 3:2, 12). The sentence beginning with "wherefore," interrupted by the parenthesis confirming the argument from Ps 95:7-11, is completed at Heb 3:12, "Take heed," &c.
      Holy Ghost saith--by the inspired Psalmist; so that the words of the latter are the words of God Himself.
      To-day--at length; in David's day, as contrasted with the days of Moses in the wilderness, and the whole time since then, during which they had been rebellious against God's voice; as for instance, in the wilderness (Heb 3:8). The Psalm, each fresh time when used in public worship, by "to-day," will mean the particular day when it was, or is, used.
      hear--obediently.
      his voice--of grace.

JFB.