Jiang Ziya, also known as Khuong Thai Cong, is a legendary figure in Chinese history. He is the founder of the Zhou Dynasty and is revered as one of China's greatest saints.

The story of Jiang Ziya fishing with a straight blade is one of the most famous stories about him. The story goes that Khuong Tu Nha went to the Yellow River to fish. He sat on the riverbank every day, but never caught a single fish. One day, a man came and asked Jiang Ziya what he was doing. Khuong Tu Nha said that he was fishing. The man asked if he had caught any fish. Khuong Tu Nha said that he had not caught any fish. The man asked what hook he used. Jiang Ziya said that he was using a straight hook. The man said that he would never catch a fish with a straight hook. He said that Jiang Ziya needed to use a curved hook. Jiang Ziya said he knew he would never catch a fish with a straight hook, but he persisted in fishing.

One day, after many days of persistent fishing, Khuong Tu Nha finally caught a big fish. The big fish told Khuong Tu Nha that he was a man of strong will and that he would succeed in everything he did. Khuong Tu Nha was overjoyed and knew that he was helped by the gods.

The story of Khuong Tu Nha fishing with a straight blade is a story of strong will and faith. It teaches us that if we persevere and believe in ourselves, then we can achieve anything we want.