A healthy dose of thanks[1]
וזאת תורת זבח השלמים אשר יקריב ליקוק: אם על-תודה יקריבנו
This is the law of a shelamim offering, which shall be brought for Hashem: If you’ll bring a thanksgiving offering…[2]
Our Sages teach us[3] that there are four people that need to express thanks by bringing a korbon Todah, a thanksgiving offering. One of them includes someone who was critically ill and recovered. The reason they are obligated is so that they keep in mind that true healing comes from Hashem. A person could, G-d forbid, make a mistake and assume everything was natural or due to modern medicine, leaving Hashem out of the picture. True, Hashem gives us the permit[4] and option to heal ourselves using doctors and modern medicine. However, to avoid forgetting Hashem, one must bring an offering upon healing.