The Last Word
Why did Ya'akov say, "Now you lack nothing but prayer," after the brothers had prepared gifts and money? Surely the correct approach would be to pray first to God for success, and then seek a natural means by which God might send salvation?
However, it could be argued that this, precisely, was Ya'akov's complaint to his sons. Yehudah had suggested that returning Shimon was an entirely straightforward matter that could not possibly go wrong: "For if we had not delayed (due to your hesitation), we would have already returned by now twice in this (time, and you would not have been troubled all these days by Shimon's absence)" (v. 10).
Therefore, Ya'akov warned his sons, "Even if it is true, as you say, that there is no danger here, you still need to pray to God. Don't just pray to God when you feel it is an emergency. You need His help for a natural plan to succeed too."
From this we can learn that a person should not only turn to God when he feels he is lacking something. He should also ask God for things which he perceives will inevitably come his way. For, in truth, God is the only provider, whether the blessing comes naturally or supernaturally.