Was eternal life promised by the Mosaic Law?

> John 3:16 (NIV) 16 For God so loved the world that he gave his one and > only Son, that whoever believes in him shall not perish but have > **eternal life**. The New Testament clearly tells us how one can attain salvation or eternal life. What about Old Testament? Was there any promise of eternal life associated with any of the Mosaic Law. For instance, was animal sacrifice promised with eternal life? How can we understand this verse? > Matthew 19:16 (NIV) > Just then a man came up to Jesus and asked, “Teacher, what good thing > must I do to get **eternal life**?” If the rich man was a Jew, he must have known how to attain eternal life from the Torah.