THE MEANING OF yesterday's vote in the Israeli Cabinet accepting the massacre inquiry report is that Prime Minister Menachem Begin and all of his colleagues save one, Defense Minister Ariel Sharon, have done what they had to do. Since Mr. Sharon, the figure most hurt by the report, has been Mr. Begin's political partner and in many ways his strategic mentor, it must have been an excruciating personal as well as political decision for the prime minister. But to turn his back on a document carrying the report's immense political and moral weight would have further convulsed the Israeli nation and savaged the legitimacy of Mr. Begin's rule.

Is it premature to say that Ariel Sharon and the tendencies he represents in Israeli society have been dealt a blow from which they cannot recover? Mr. Sharon's brilliance as a strategist and military commander has vastly outraced his political judgment. He has brought Israel triumphs of a sort that it can scarcely sustain. The Beirut massacre, for which the commission found that he had the largest individual share of Israel's collective indirect responsibility, was an outcome consistent with his stark definition of Israel's relationship to its Arab neighbors and with his faith in force as the solution of Israel's international cares.

Israel's parliamentary and political ways are complicated, and so it is not possible to know the next steps in the Israeli drama. The recommendations of the report affect the careers and reputations not only of Mr. Sharon--his resignation or dismissal is called for--but a number of other high military and civilian officials. Apart from the recommendations affecting individuals, moreover, the report has pitched Israel into a passage of introspection and political review at one and the same time. The most painful and complex decisions are being required, then, of Mr. Begin and the country as a whole. In these circumstances, it is heartening to those who wish Israel well to see that the prime minister, in his first post-report test, has not shied away from what is required of him.