Harden not (μη σκληρυνητε). Prohibition with μη and first aorist (ingressive) active subjunctive of σκληρυνω, late verb from σκληρος (dried up, stiff, hard) as in Acts 19:9; Romans 9:18.

As in the provocation (ως ην τω παραπικρασμω). Late compound from παραπικραινω, late verb to embitter (παρα, πικρος), found only in LXX and here and verse Hebrews 3:15. It means embitterment, exasperation. For the simple verb πικραινω, to make bitter, see Colossians 3:19. The reference is to Meribah (Hebrews 17:1-7).

Like as in the day (κατα την ημεραν). "According to the day" as in Acts 12:1; Acts 19:23.

Of the temptation (του πειρασμου). The reference is to Massah which took place at Rephidim.