Who said "You don't know what today brings. Prepare day and night."?

Yamamoto Tsunetomo (1659–1719). Source: Hagakure, Book 1.

What is the original Japanese?

武道は今日の事も知らずと思ひて、日々夜々に箇條を立てゝ吟味すべき事なり. Translated from the original Japanese by Spartan Surfers.

You don't know what today brings. Prepare day and night.

The source

"You don't know what today brings. Prepare day and night." Yamamoto Tsunetomo said it in Hagakure, Book 1. Translated from the original Japanese by Spartan Surfers.

"武道は今日の事も知らずと思ひて、日々夜々に箇條を立てゝ吟味すべき事なり"

Original Japanese, Hagakure, Book 1. Japanese: Hagakure, vol. 1 (1937 printing), NDL digital text.

Who said it

Yamamoto Tsunetomo (1659–1719). Samurai turned monk whose spoken reflections were written down as Hagakure, Hidden by Leaves.

Questions

Who said "You don't know what today brings. Prepare day and night."?: Yamamoto Tsunetomo (1659–1719). Source: Hagakure, Book 1.
What is the original Japanese?: 武道は今日の事も知らずと思ひて、日々夜々に箇條を立てゝ吟味すべき事なり. Translated from the original Japanese by Spartan Surfers.