Rabbi Nissim ben Moshe in "Ma'aseh Nissim" wrote on Sefer Shemot:
"ועניין הסנה שאיננו אוכל והוא בוער באש, וראית מלאך ה' בסנה - כל זה מהמין קראתיו "אות". והסנה משל לעם ישראל הבוער תמיד באש השעבוד ובשלהבת הצרות ובעבודת פרך..."
"And what happened with the bush that it wasn't consumed and it is burning with fire, and the seeing of the angel of Hashem in the bush - all of this is of the type of a "sign". And the bush is a parable to the Nation of Yisrael who are constantly burning in the fire of the slavery and in the flame of the troubles and the hard work..."
According to the footnotes, an "אות" or a "sign", as explained earlier in the book, is an imaginary occurrence, either in the mind or during a dream of the prophet and is not materially real.
"ואלה האותות השלשה שנעשו בין השם ית' למשה - כבר כתבנו שסובל היותם מהמין קראתיו "אות", או מהמין קראתיו בשם "נס".
"And these are the signs three that were between Hashem and Moshe - we already said that it can endure their being of the type of "sign", or from the type of "miracle".
According to the footnote and further explaining in the book, the signs, when shown to Moshe, were only prophetic and didn't happen. When he showed them to Am Yisrael, they did actually happen.
"ואמנם עניין צפורה, ואמרו (שמות ד' כד): ויהי בדרך במלון ויפגשהו ה' ויבקש המיתו" - יש מי שפירש שבא חולי ורעדה ותמהון לבב למשה בהיותו נבוך בעניניו ואמר: אם אמול הבן בדרך, יסתבכן. ואם לא אמול אותו עד הגיענו למצרים ואחר המנוחה מעמל הדרך, יאמרו ישראל עלי: ראו זה בא להזהירנו על מצות השם...והוא בלתי נזהר...ועל זה נשאר משה טרוד המחשבות, נבהל הרעיונים, עד שהתעוררה צפורה למול הבן במלון ושילך משה יחידי למלאת שליחות השם ית'...אם כן, יהיה זה מהמין השני מהחלק השני.
"And that which happened with Tzipporah, and it is said (Shemot 4:24): "At a night encampment on the way, the LORD encountered him and sought to kill him" - there are those that explained that a sickness and a shiver and confusion of the heart befell Moshe from his nervousness in his dealings and saying: "If I circumcise the child on the road, I will endanger him. And If I don't circumcise him until we reach Egypt and after we rest from the trip, Yisrael will say about me: See whom has come to warn us about the commandments of Hashem...and he isn't careful...and for this Moshe was troubled by his thoughts, until Tzipporah rose to circumcise their son at the encampment and that Moshe should go by himself to fulfill the mission of Hashem...and if so, this shall be from the second type of the second part." [Which is a strange occurrence that shouldn't be understood as pshat, i.e., not as a miracle]
"ואמרו..."ולכל בני ישראל לא יחרץ כלב לשונו..."...יש מי שפירש שרמז לכלב השמימיי, שממנו קטב מרירי...והנכון בעיני, שנאמר זה על בני האדם הרעים ובעלי לשון הרע...כי מרוב פחדם ויראתם בצאת בני ישראל ממצרים לא ימצא איש מצרי רשע רע שיקללם..."
"And that which is said..."but not a dog shall snarl at any of the Israelites..."...there are those who explained that it is a hint to the heavenly dog, from which came the Ketev Meriri...and the correct explanation in my eyes, that it was said all those evil men and those who had an evil tongue...for out of great fear at the leaving of Bnei Yisrael from Egypt there could not be found an evil Egyptian man who would curse them..."
Later, he brings a few different explanations for what happened at Yam Suf and tells the reader to choose whichever he likes best - but to be aware that these all fall under the category of "מופת" - uncommon things in nature with the wonderous part being the prophet's ability to predict these events.