וַיֹּ֨סֶף ע֥וֹד דָּוִ֛ד אֶת־כָּל־בָּח֥וּר בְּיִשְׂרָאֵ֖ל שְׁלֹשִׁ֥ים אָֽלֶף׃
Rashi on II Samuel
All the chosen men of Yisroel, thirty thousand. Because they gathered for him when they crowned him in Chevron and [therefore] this was a second gathering [for Dovid] [Scripture] herefore says, "[Dovid] again gathered."