Rabbi Chayim Palachi (Turkey, 1788-1868), in his work Kaf Ha'chayim (21:2), discusses the importance of saying "Im Yirtzeh Hashem" "God willing" before every undertaking. This concept is alluded to in the verse in Mishlei (19:21), "Va'atzat Hashem Hi Takum" (literally, "the will of God will always be upheld"). The word "Hi" is spelled with the three letters "Hei," "Yod," "Alef," the first letters of the phrase "Im Yirtzeh Hashem." This verse thus hints to the fact that by reminding oneself of his dependence on God for success in any undertaking, even the small and seemingly simple actions we perform, his actions will be "upheld" and successful. It is therefore recommended that one accustom himself to saying "God willing" or other, similar expressions, such as "Ve'im Yigzor Hashem Ba'chayim" ("If Hashem will decree life upon me") or "Be'ezrat Hashem" ("With God's help"), to express his awareness of his dependence on God. Rabbi Chayim Palachi guarantees that a person who is accustomed to reciting these phrases before beginning any undertaking will be granted success.
In this context, Rabbi Chayim Palachi discusses as well the need to maintain a delicate balance between necessary effort in securing a livelihood, and excessive, undue vigilance in one's professional life. The Sages comment (Masechet Megila 6b), "Yagati U'matzati Ta'amin" that a person can succeed and achieve only through proactive and concentrated effort. One cannot sit idle at home and expect to earn a living. At the same time, however, the verse in Mishlei (28:20) states, "One who exerts himself to become wealthy will not be cleansed." Meaning, one must not invest excessive time and energy in the pursuit of wealth. After all, the Almighty determines how much wealth a person will receive, and His decision will materialize regardless of how much effort one exerts. At times a person can earn a fortune without much effort, or earn very little even after a considerable investment of time and energy. A careful balance must therefore be maintained between the need to pursue a career to earn a living, and ensuring not to devote oneself excessively to the pursuit of wealth.
To help one maintain this delicate balance, Rav Chayim Palachi advises that we bear in mind the possibility of falling ill as a result of overloaded work schedules. No person is prepared to sacrifice his health and general well-being for the sake of wealth. It is therefore advisable to recall at all times the potential health dangers of excessive work, as this will help ensure a proper balance between professional activity and other pursuits.
Summary: It is proper to accustom oneself to saying "Im Yirtzeh Hashem" ("God willing") or similar expressions before undertaking even seemingly simple tasks, as this can help ensure success. In one's professional life, Judaism encourages a person to work for a livelihood while ensuring not to devote himself excessively to his work, and to rather trust in the Almighty's ability to provide even without an inordinate investment of time and energy.
