Where in the bible does say about thou shall not waste thy seed?

The phrase "thou shall not waste thy seed" is often associated with the story of Onan in the Book of Genesis. In Genesis 38:9-10, Onan is instructed to fulfill his duty to his deceased brother by producing offspring, but he spills his seed on the ground instead, leading to God's displeasure. This passage is sometimes interpreted as a prohibition against wasting semen, although interpretations can vary widely among religious scholars and traditions.