וַיִּבְכּוּ֩ בְנֵ֨י יִשְׂרָאֵ֧ל אֶת־מֹשֶׁ֛ה בְּעַֽרְבֹ֥ת מוֹאָ֖ב שְׁלֹשִׁ֣ים י֑וֹם וַֽיִּתְּמ֔וּ יְמֵ֥י בְכִ֖י אֵ֥בֶל מֹשֶֽׁה׃
And the children of Israel wept for Moses in the plains of Moab thirty days; so the days of weeping in the mourning for Moses were ended.
Read kabbalistic (mystical) interpretation of Deuteronomy 34:8: and classical mystical sources.