A chassid hid in the Yismach Yisrael's zt'l room to watch his Rebbe prepare and light the Chanukah lecht. The chassid watched the Rebbe's joy and hislahavus as he poured the oil and prepared the wicks, but when the Rebbe lit the lecht, his avodah seemed very regular. He didn't see anything unique. The chassid wondered, "Shouldn’t the mitzvah be performed with even greater hislahavus than the preparations?"
He couldn’t come out of his hiding place to ask the Rebbe this question since he was there without permission, so he kept his questions to himself.
The next day, the Yismach Yisrael approached the chassid and said, "A person's part in a mitzvah is his preparations. The actual performance of the mitzvah isn't in his hands anymore. Either Hashem gives him inspiration, or He doesn't."
The Chofetz Chaim zt'l told the following mashal: An oil merchant once came to town. The townspeople brought pots and containers and asked the merchant to fill them with oil. When all their vessels were filled with oil, the merchant said, "You want to buy more oil, and I want to sell you more oil. But I can't sell you oil if you don't have containers."
This mashal helps us understand why it is important to prepare for Chanukah lecht. Hashem wants to give us light, kedushah, brachos, and salvations on Chanukah, but we can’t receive it without enough vessels. Every preparation creates another vessel into which Hashem will pour His blessings.
Rebbe Dovid Moshe of Chortkov zt'l said: Place a gem on a velvet cloth, and it appears beautiful. Put the gem in a gold ring, and it seems exquisite. Place the same stone in a paper bag or a dirty bowl, and it won’t have the same appeal. The same is true with the light of Chanukah. We must create a setting that is conducive for it to shine beautifully. This is hinted at in the words אור היה ישראל בני ולכל במושבת (Shemos 10:23). The אור, brilliant light of Chanukah variates, במושבתם, with its setting. The setting is created with our preparations. If we prepare ourselves well, we become a proper receptacle to retain the great light of Chanukah.
A young man arrived at the Beis Yisrael's residence. He told the gabbai, Reb Chanina Shiff, "My grandfather, the Biala Rebbe (Rebbe Yechiel Yehoshua of Biala zt'l), sent me here to watch the Beis Yisrael as he prepares for Chanukah lecht." The gabai opened the door and saw the Rebbe pacing in his room, his face aflame. The gabai quickly shut the door and said to the young man, "I don't dare disturb the Rebbe now. If you want to, go in on your own." The grandson opened the door, but when he saw the Beis Yisrael's holy face aflame, he too, quickly shut the door. He was afraid to disturb him. He returned to his grandfather and told him what he saw. His grandfather replied, "That's exactly what I wanted you to see."