Hebrews 10:26

We sin willfully [ε κ ο υ σ ι ω ς α μ α ρ τ α ν ο ν τ ω ν η μ ω ν]. JEkousiwv willfully, only here and 1 Peter 5:2. Comp. Philippians 1:14, kat' eJkousion of free will. See LXX, Numbers 14:3. The willful sin is the abandonment of Christianity for Judaism.

The knowledge [ε π ι γ ν ω σ ι ν]. Only here in Hebrews. Very common in Paul. For the word, and the phrase knowledge of the truth, see on 1 Timothy 2:4. The truth is the revelation through Christ.

There remaineth no more sacrifice for sins [ο υ κ ε τ ι π ε ρ ι α μ α ρ τ ι ω ν α π ο λ ε ι π ε τ α ι θ υ σ ι α]. Of course not. For the Levitical sacrifices are abolished. It is Christ's sacrifice or none.