It states (Koheles 9:10) לעשות ידך תמצא אשר כל עשה בכחך, "Whatever you can do with your might, do it." The Baal Shem Tov zt'l says that בכחך means thoughts, chachmah (because חכמה spells ח"כ מה). So, the pasuk is telling us ידך תמצא אשר כל בכחך לעשות, if you have a good thought, an idea that can bring forth a kiddush Hashem or kindness to others, עשה, do it right away. Don't procrastinate.
Good thoughts come from Above, and if you don't act upon them right away, your inspiration will wane and vanish, and you will probably never get around to doing the good deed. So, if you have a good idea, it is a message from heaven. Act immediately. Capture the moment and the opportunity.
At the beginning of the parashah, Rashi writes, "What did Yisro hear that caused him to come? He heard about kriyas Yam Suf and milchemes Amalek." What specifically about Kriyas Yam Suf and milchemes Amalek inspired Yisro to come to the desert to receive the Torah?
The Sar Shalom of Belz zt'l explains that, generally, before a person travels, he must close his businesses, sell his property, say goodbye to friends, and make other arrangements. One doesn't just pick up and go. So why did Yisro come so suddenly? We know that he rushed because he arrived before Shavuos! We understand that Kriyas Yam Suf inspired him to join the Jewish nation, but why the rush?
The answer is that Yisro heard about milchemes Amalek. Yisro understood that Amalek could have only come by acting quickly, without thinking. Had Amalek taken some time to think things over, he would have realized that it was suicidal to battle the Jewish nation, to whom Hashem performed miracles, ten makos, and kriyas Yam Suf. Yisro realized that he must do the same by acting immediately. If he dallies and thinks things over, he will never come. He was inspired, so he had to act on his inspiration immediately.
The Yesod HaAvodah says that it is alluded to in the pasuk (Tehillim 111), טוב שכל, if you have a good thought, עשיהם לכל, bring it to action.
When Hashem offered the Torah to the Jewish nation, they replied, ונשמע נעשה. They didn't ask, "What is written in the Torah?" Instead, they jumped in and accepted the Torah. This is often the only way to excel in avodas Hashem.
