For some, when they had heard, did provoke: howbeit not all that came out of Egypt by Moses.
For some - rather, interrogatively, 'For WHO was it that, when they had heard (referring to "if ye will hear," Hebrews 3:15), did provoke (God)?' It might have been objected, that the great blessings which Paul had said Christians enjoy ensure them against apostasy. Nay, he replies, Were not they who were shut out from the Canaan rest the very persons, all of them, who came out of Egypt by God's mighty arm under Moses? Ye need to take heed against unbelief: for, was it not because of unbelief that all our fathers were excluded? (Ezekiel 2:3.) "Some," and "not all" (namely, not those under twenty years old, the women, the Levites, Numbers 1:47, Joshua, and Caleb), would be a faint statement of his argument, when his object is to show the universality of the evil. Not merely some, but all the Israelites; for the solitary exceptions, Joshua and Caleb, are hardly to be taken into account in so general a statement (Numbers 26:64-65). So Hebrews 3:17-18 are interrogative:
(1) The beginning of the provocation, soon a fter the departure from Egypt, is marked in Hebrews 3:16;
(2) The 40 years of it in the wilderness, Hebrews 3:17;
(3) The denial of entrance into the land of rest, Hebrews 3:18. Note, cf. 1 Corinthians 10:5.
Howbeit - `Nay (why need I put the question), was it not all that came (Paul does not say, were led: for they soon ceased to follow God's leading) out of Egypt?' (Exodus 17:1-2.)
By Moses - as their leader.