The Maasei L’melech imparts a deep insight regarding learning: “Most mitzvos are time-centric. Some must be fulfilled by day, others at night. Yet other mitzvos have their own precise times when they are fulfilled: some weekly, some monthly, some yearly, or with at even less frequent intervals.
“Torah study is an exception to this rule. As the verse states, ‘Vehigisa bo yomam volayloh — And you shall contemplate them day and night.’ Every available instant is earmarked for learning whenever possible. Every instant, we must ask ourselves if we can learn, and if this is possible, we must use the moment to learn.
“On Megillah 3, we find that when an angel came to rebuke Yehoshua, he was unsure whether the angel came because they did not bring the korban tomid or because of bitul Torah. When the angel came to Yehoshua and said, ‘I have come now,’ Yehoshua understood that the angel was there due to bittul Torah. But if this merely means that one can tell from the timing of the angel’s appearance that he came due to bittul Torah, why did Yehoshua ask? We must say that the angel’s response, ‘I came now,’ is not merely an obvious rejoinder. ‘Now’ indicates that the angel came specifically for the needs of that very instant—to tell them the importance of using every available moment for Torah. When Yehoshua heard this, he immediately began to delve into the vast depths of halacha” (Maasei L’melech, Parshas Eikev).