Deuteronomy 34:8 in the King James Version
And the children of Israel wept for Moses in the plains of Moab thirty days: so the days of weeping and mourning for Moses were ended.
Context
7 Moses was one hundred twenty years old when he died. His eye was not dim, nor his strength gone.
8 The children of Israel wept for Moses in the plains of Moab thirty days, until the days of weeping in the mourning for Moses were ended.
9 Joshua the son of Nun was full of the spirit of wisdom, for Moses had laid his hands on him. The children of Israel listened to him, and did as the LORD commanded Moses.