Search tmux scrollback with the landmarks you remember, watch the exact range highlight in the pane, then paste it at your cursor without submitting it.
The text you need next is usually already on your screen. A pod name three commands back, the error string you want to search for, a URL a tool printed, the long flag you typed twenty minutes ago. Getting it into your current prompt means reaching for the mouse, and the mouse gets it wrong: a soft-wrapped line comes back with a newline in the middle, and a newline in a shell paste runs the command. This post covers a tmux plugin that selects the range by the words you remember, shows you the selection in the real pane while you type, and pastes it without submitting it.
Mouse selection has no idea where a logical line begins. tmux wraps a long command across three display rows, you drag across all three, and you paste something with two line breaks in