והיה אם לא יאמינו גם לשני האתות האלה ולא ישמעון לקלך ולקחת ממימי היאר ושפכת היבשה ... (ד-ט)
Moshe Rabbeinu was instructed by Hashem to perform three miraculous signs - אותות - for the Jewish people to prove to them that he was indeed Hashem’s emissary. The first, due to his questioning of their emunah, was to throw down his staff, which would then transform into a snake. This symbolized the fact that he spoke negatively about them. The second was his hand becoming inflicted with tzaraas. Seemingly, this too represented his negative words spoken concerning them. Why were two separate signs representing the identical idea required? Additionally, the third and final sign was pouring water and it turned to blood as it hit the ground. What was the significance of this?
Perhaps we can offer the following machshava. The first אות indeed showed Divine retribution for speaking unfavorably about Klal Yisroel. The second and third signs were meant to convey an entirely different message. צרעת is a נגע that is ostensibly an עונש - a punishment. However, in Parshas Metzorah, we are also taught that when צרעת would appear on the walls of a house, it would ultimately have to be demolished, sometimes unearthing a hidden treasure inside the walls. Thus, essentially, after one would recognize the message and repent, the נגע would be converted to an ענג - a reward.
The third אות was to pour water on the ground where it would turn into blood. Both of these signs were messages from Hashem that although what was transpiring in Mitzrayim with the slavery and bondage seemed harsh, they were essentially good things. Just like with tzaraas, you will find the treasure, and what is seemingly blood on the ground is, in fact, pure water from above. Similarly, the message being given was, all the צרות in Mitzrayim are part of His master plan.
May we internalize this message and always remember that כל מה דעביד רחמנא, לטב עביד. Then, and only then, can we be zoche to see the treasure unearthed and witness the light at the end of this golus tunnel, בב"א.