Observe and hear all these words that I command you, in order that it may go well with you and with your children after you forever, when you do what is good and right in the eyes of Hashem your God.
English: “Observe and hear” — It was taught: One who says “Behold I am obligated for a todah without its bread and a sacrifice without its libations,” and they said to him “Bring the todah and its bread, the sacrifice and its libations,” and he said “If I had known that this is so I would not have vowed” — they compel him and say to him “Observe and hear”: “Observe” — bring the todah and its bread, the sacrifice and its libations; “and hear” — that you should not be accustomed to do so.
On the daf / in context: The double language is applied to enforce both the fulfillment of a vow according to its full requirements and a caution against repeating incomplete vows.
Type of Learning
Derash on the verse (Sifrei) — compelling full performance of a vow.
What Is Learned
One who vows a todah or sacrifice is compelled to bring it with its full accompaniments, and is cautioned not to make incomplete vows in the future.